A new tank without cycling
 

amosf © Tim Fairchild wrote:

Tynk wrote:


amosf © Tim Fairchild wrote:

nut wrote:


Tynk wrote:

Kind of like the old, or rather better said, not current generation
still telling folks the "one inch per gallon rule". = )~

Is the one-inch-per-gallon rule no longer valid?!

Nobody told me... when did this happen?

It uses a linear measure to calculate a volume. It can never and could
never have worked, an I can't imagine who ever came up with a silly rule
like that. A 60 inch fish goes in a 60 gallon tank? Cool.

In any case, it's a metric world these days and who the heck knows what
an inch and a gallon is anyway. Only the US uses that stuff these days :)

You know Tim,
If the teacher and ones in charge would have switched over long ago we
would all be on the same page with that. I cannot figure out most
metric, as I am from the US.
The simple things, sure. Things we Americans use all the time. 1 & 2
liter bottles, centimeters, a yard, etc. I'm lost when it comes to much
else. = /


It's a pity... But oh well. I notice it the most on aquarium lists as it's
always about measures - so there is always converting to do :)


Each week I go through the paper looking at the second hand aquariums
for sale - for when I have money for my next one - half the sizes are in
metric and half in imperial. I still have to read with my calculator
next to me to get a gut feel for the size of the tanks.

A new tank without cycling
 

Tynk wrote:

Jim Morcombe wrote:


Keep doing the filter "swish". It is rich in bacteria.


Not according to scientists.
It's rich in muck.

Do you have a refernce on that? Speaking as a scientist, I think it is
rich in bacteria. (AlthoughI am not a microbiologist)

A new tank without cycling
 

Zëbulon wrote in
:


"nut" wrote in message
...
Zëbulon wrote:
"Tynk" wrote in message
oups.com...
You cannot set such a vague "rule" when there are way too many
variables when it comes to stocking a fish...much more than it's
size in inches.
======================
Such as the fact a 1" goldfish passes a lot more waste than a 1"
guppy.

The rule was for tropical fish, not coldwater.
=================
This is true but how many newbies know that? They come here all the
time asking about putting tropicals with goldfish. Some people keep
them together successfully.

Also, some tropicals have a lot more bulk per inch than others.

It would be good to have something a little more accurate than the inch
per gallon guide. In one article I read, they made the excellent
suggestion that the "real" main limiting factors for an aquarium are
mass of fish as adults vs. water surface area of the tank (which is a
more measurable equivalent to oxygen transfer rate), with different
stocking ratios for Fresh, brackish, salt, (and warm and cold) waters.

You could further modify this by multiplier factors considering things
like whether additional oxygenation/waste management is available
(airstone, planted tank etc), or fractional multipliers for if you're
keeping only carnivorous fish (more waste). The main advantage is that
you get a better feel for the differences in body types. The drawback
is that I haven't found many sources which report average/typical adult
fish mass. This is one of them;

http://www.aquariumfish.com/aquarium...aid=323&cid=53
&search

For common freshwater species, that table gives you neons at 0.2g and
7cm discus at 19 g. If anyone knows of other resources which report
more adult typical mass values for FW aquarium species, I'd love to see
it. I could bring my fish into work, and weigh each immersed in a fixed
volume in a graduated cylinder (and then weigh the water afterwards to
calculate their mass), but I'd rather save them the stress of such a
trip.

Even after all that, metabolic rate doesn't scale directly with mass of
the fish, but this would be a step in a more accurate direction.

DaveZ
Atom Weaver

A new tank without cycling
 

Jim Morcombe wrote:
Tynk wrote:

Jim Morcombe wrote:


Keep doing the filter "swish". It is rich in bacteria.


Not according to scientists.
It's rich in muck.

Do you have a refernce on that? Speaking as a scientist, I think it is
rich in bacteria. (AlthoughI am not a microbiologist)

Well, research a scientist named Peter Strom. He's an environmental
scientist that has been studying nitrifying bacteria for the past 30
yrs.
His name is tossed out because simply because he was recently written
about in the January edition of Tropical Fish Hobbyist, but I have
learned about this being the case a few years ago.
Also, you can find more about the correct bacteria on the BioSpira info
page at Marineland.com.
Like I mentioned before, this is relativly new information that was
learned within the last 10 yrs (give or take).
I think abut it this way....if these starter nitrifying bacteria
secrete such a sticky substand that not even hard, rushing water can
get them to break loose, how is swooshing a filter going to get them
loose?
They also adhere to more solid surfaces, not goo or gunk that floats
about.
Of course there are a few out there loose, but not enough to cycle a
tank with.
This is why adding a filter pad, gravel, plants, etc., from an
established tank with a more solid surface is the best way because it
will have the most bacteria stuck to it.
Folks that know what they're doing and know how to keep a fishtank
healthy will be doing major water changes and gravel vacs while cycling
a tank with fish. Of course the knowldegeable would lose the least
amount of fish doing so.
Now the ones that swoosh a filter pad (only) in a newly cycling tank,
or use old tank water, may *think* they just added N. bacteria and
started the process, but with their water changes and good tank
maintenance their cycling process is simply less harmful to the fish
they are using. This is because of the water changed and gravel vacs
and had nothing to do with adding old water or gunk from a filter pad.
You're actually just adding debris and old water. I understand this is
a bit hard to believe, as I had a hard time believing it at first.
I used to be under the same impression that by adding debris and old
tank water I was adding the N. bacteria. Now, however, I have learned
otherwise.

As for the side conversation going on (I know I started it with my
comment, sorry) about the one inch per gallon rule being ridiculous, it
really doesn't fit anywhere.
It's no good for newbies, as it just screws them up right off the bat.
I have spoken to countless newbies who have a 10g tank with a few
Oscars, some have a hodge podge of fish that have no business being
together in a tank....but will justify it because it's the right amount
of inches...some that keep buying Discus and they keep dying, but their
Mollies and Tiger Barbs are fine. I hear all sorts of crazy things.
Things that will make a seasoned hobbyist's head spin (several times
before exploding).
99% of the time it always goes back to that stupid "rule".
And for the person who is thinking that newbies don't buy Discus, or
certain Cichlids, etc...oh they do. All too often.
Besides the stupid "rule", another huge problem in the hobby is shop
employees that do not have a clue as to what they're doing, or know
anything about the fish they are selling.
Just last week I was trying to convince a Petsmart employee that he
couldn't add Neons to his newly set up 75g that he already had a Black
Moore and several Platies in.
Besides the whole..new tank syndrome being very bad for Neons, I tried
to explain the whole *don't mix tropicals iwth cold water fish" thing
to him. This was lost on him.
I got the usual response...they look fine, and seem happy.
:: My head has started to spin already::
Then he asks well what would be good to put in it, I reply a couple
more Goldifsh and that's it.
He thought I was nuts and after explaing how large his Moore would grow
to and he thought I was out of my mind, or messing with him. He said
they don't get that large...no way. That's the size of a Koi. I said
yeah, a baby Koi.
:: head has since exploded and is still spinning::
I explained to him to please research Black Moores when he gets home,
and that Koi get like 30" long and should be in a pond, not a
tank...again, he's like Nooooo. Ok, I add research them too.
This guy is giving out "advice" on a daily basis to many newbies out
there.
He's just one guy. Look how many folks have horror stories of shop
employees spreading bull doo doo to the unknowing.
Now do understand that I spoke in a calm, nice mannor to this kid. It
was difficult, but I managed to do it.
I ended the conversation with him like this....
You work in a pet shop. You have fish tanks at home with fish you don't
know about, and that shouldn't be mixed together. You should really
learn about the creatures you are both selling and keeping. It's very
important.
He said he would Google Moores when he got home and bet he wouldn't
find anything about them getting around 8" long and a girth about the
size of a small orange.
I really hope he did. Not so I would be proven right, but for his own
knowledge, his fish, and the newbies he "advises".

A new tank without cycling
 

Tynk wrote:
Jim Morcombe wrote:
Tynk wrote:

Jim Morcombe wrote:


Keep doing the filter "swish". It is rich in bacteria.


Not according to scientists.
It's rich in muck.

Do you have a refernce on that? Speaking as a scientist, I think it is
rich in bacteria. (AlthoughI am not a microbiologist)

Well, research a scientist named Peter Strom. He's an environmental
scientist that has been studying nitrifying bacteria for the past 30
yrs.
His name is tossed out because simply because he was recently written
about in the January edition of Tropical Fish Hobbyist, but I have
learned about this being the case a few years ago.
Also, you can find more about the correct bacteria on the BioSpira info
page at Marineland.com.
Like I mentioned before, this is relativly new information that was
learned within the last 10 yrs (give or take).
I think abut it this way....if these starter nitrifying bacteria
secrete such a sticky substand that not even hard, rushing water can
get them to break loose, how is swooshing a filter going to get them
loose?
They also adhere to more solid surfaces, not goo or gunk that floats
about.
Of course there are a few out there loose, but not enough to cycle a
tank with.
This is why adding a filter pad, gravel, plants, etc., from an
established tank with a more solid surface is the best way because it
will have the most bacteria stuck to it.
Folks that know what they're doing and know how to keep a fishtank
healthy will be doing major water changes and gravel vacs while cycling
a tank with fish. Of course the knowldegeable would lose the least
amount of fish doing so.
Now the ones that swoosh a filter pad (only) in a newly cycling tank,
or use old tank water, may *think* they just added N. bacteria and
started the process, but with their water changes and good tank
maintenance their cycling process is simply less harmful to the fish
they are using. This is because of the water changed and gravel vacs
and had nothing to do with adding old water or gunk from a filter pad.
You're actually just adding debris and old water. I understand this is
a bit hard to believe, as I had a hard time believing it at first.
I used to be under the same impression that by adding debris and old
tank water I was adding the N. bacteria. Now, however, I have learned
otherwise.

As for the side conversation going on (I know I started it with my
comment, sorry) about the one inch per gallon rule being ridiculous, it
really doesn't fit anywhere.
It's no good for newbies, as it just screws them up right off the bat.
I have spoken to countless newbies who have a 10g tank with a few
Oscars, some have a hodge podge of fish that have no business being
together in a tank....but will justify it because it's the right amount
of inches...some that keep buying Discus and they keep dying, but their
Mollies and Tiger Barbs are fine. I hear all sorts of crazy things.
Things that will make a seasoned hobbyist's head spin (several times
before exploding).
99% of the time it always goes back to that stupid "rule".
And for the person who is thinking that newbies don't buy Discus, or
certain Cichlids, etc...oh they do. All too often.
Besides the stupid "rule", another huge problem in the hobby is shop
employees that do not have a clue as to what they're doing, or know
anything about the fish they are selling.
Just last week I was trying to convince a Petsmart employee that he
couldn't add Neons to his newly set up 75g that he already had a Black
Moore and several Platies in.
Besides the whole..new tank syndrome being very bad for Neons, I tried
to explain the whole *don't mix tropicals iwth cold water fish" thing
to him. This was lost on him.
I got the usual response...they look fine, and seem happy.
:: My head has started to spin already::
Then he asks well what would be good to put in it, I reply a couple
more Goldifsh and that's it.
He thought I was nuts and after explaing how large his Moore would grow
to and he thought I was out of my mind, or messing with him. He said
they don't get that large...no way. That's the size of a Koi. I said
yeah, a baby Koi.
:: head has since exploded and is still spinning::
I explained to him to please research Black Moores when he gets home,
and that Koi get like 30" long and should be in a pond, not a
tank...again, he's like Nooooo. Ok, I add research them too.
This guy is giving out "advice" on a daily basis to many newbies out
there.
He's just one guy. Look how many folks have horror stories of shop
employees spreading bull doo doo to the unknowing.
Now do understand that I spoke in a calm, nice mannor to this kid. It
was difficult, but I managed to do it.
I ended the conversation with him like this....
You work in a pet shop. You have fish tanks at home with fish you don't
know about, and that shouldn't be mixed together. You should really
learn about the creatures you are both selling and keeping. It's very
important.
He said he would Google Moores when he got home and bet he wouldn't
find anything about them getting around 8" long and a girth about the
size of a small orange.
I really hope he did. Not so I would be proven right, but for his own
knowledge, his fish, and the newbies he "advises".

As I noted in a much earlier reply on this long thread about using the
filter pad "swoosh" method of cycling, I have conducted side by side
comparisons of this method in one client where I set up several
aquariums at the same time and monitored the ammonia levels. There was
a pronounced ammonia spike with the "swoosh" method and none with a
healthy media exchange (and a reasonable amount of media was used).

As for my two cents on the inch per gallon (one cm per 2 liter?), I
have not recommended this for years, yet I will admit that for narrow
bodied fish such as neons I will still use this on occasion to explain.
But what I think is more important (and this was pointed out earlier in
the thread) are these factors:

*Surface area of the aquarium
*Type of fish, such as fish that naturally produce more waste (partly
do to the type of food they eat) such as goldfish where one fish per 8+
gallons is better.
*Filtration, a properly filtered aquarium with multiple filters is
important.
*Maintenance schedule
*New or experienced aquarist; new aquarist tend to over feed, often buy
cheap foods, listen to inexperienced PetsMart employees (LOL, could not
resist that one, but I found it to be true based on client feedback).

Carl
http://aquarium-info.blogspot.com/

A new tank without cycling
 

"Jim Morcombe" wrote in message
...
Zëbulon wrote:
This is true but how many newbies know that? They come here all the time
asking about putting tropicals with goldfish. Some people keep them
together successfully.

Also, some tropicals have a lot more bulk per inch than others.
My wife makes me keep HER goldfish in with my tropicals. It looks
strange, but it works.
====================
It works for a lot of people because GF can live quite well in warm water.
All my indoor fancy GF live with plecos and otos. The water seldom drops
below 75F in the tanks.
--
ZB....
Frugal ponding since 1995.
rec.ponder since late 1996.
My Pond & Aquarium Pages:
http://tinyurl.com/9do58
~~~~ }((((* ~~~ }{{{{(ö ~~~~ }((((({*

A new tank without cycling
 

"amosf © Tim Fairchild" wrote in message
...
Unfortunately it's not even good enough for a rough guideline. What is the
use of a rule that has more exceptions than the rule? An inch per gallon,
but not for coldwater and not for goldfish and not for loaches and not for
discus and other deep body fish and not for thick fish and not for fish
over 4 inches long and not for...
==================
It's a rule that should be retired. It's almost useless as anyone can see.
There's just too much variation in the size and bulk of the fish we keep to
be of any real use.
--
ZB....
Frugal ponding since 1995.
rec.ponder since late 1996.
My Pond & Aquarium Pages:
http://tinyurl.com/9do58
~~~~ }((((* ~~~ }{{{{(ö ~~~~ }((((({*

A new tank without cycling
 

Jim Morcombe wrote:

Zëbulon wrote:

"nut" wrote in message
...

Zëbulon wrote:

"Tynk" wrote in message
oups.com...

You cannot set such a vague "rule" when there are way too many
variables when it comes to stocking a fish...much more than it's size
in inches.

======================
Such as the fact a 1" goldfish passes a lot more waste than a 1"
guppy.


The rule was for tropical fish, not coldwater.

=================
This is true but how many newbies know that? They come here all the
time asking about putting tropicals with goldfish. Some people keep
them together successfully.

Also, some tropicals have a lot more bulk per inch than others.
My wife makes me keep HER goldfish in with my tropicals. It looks
strange, but it works.

My wife put her goldfish in my gourami tank once as well. I soon got her
another tank.

She appreciated it after one of the goldfish lost it's tail to a gudgeon.

A new tank without cycling
 

atomweaver wrote:
Zëbulon wrote in
:


"nut" wrote in message
. ..

Zëbulon wrote:

"Tynk" wrote in message
legroups.com...

You cannot set such a vague "rule" when there are way too many
variables when it comes to stocking a fish...much more than it's
size in inches.

======================
Such as the fact a 1" goldfish passes a lot more waste than a 1"
guppy.

The rule was for tropical fish, not coldwater.

=================
This is true but how many newbies know that? They come here all the
time asking about putting tropicals with goldfish. Some people keep
them together successfully.

Also, some tropicals have a lot more bulk per inch than others.


It would be good to have something a little more accurate than the inch
per gallon guide. In one article I read, they made the excellent
suggestion that the "real" main limiting factors for an aquarium are
mass of fish as adults vs. water surface area of the tank (which is a
more measurable equivalent to oxygen transfer rate), with different
stocking ratios for Fresh, brackish, salt, (and warm and cold) waters.

You could further modify this by multiplier factors considering things
like whether additional oxygenation/waste management is available
(airstone, planted tank etc), or fractional multipliers for if you're
keeping only carnivorous fish (more waste). The main advantage is that
you get a better feel for the differences in body types. The drawback
is that I haven't found many sources which report average/typical adult
fish mass. This is one of them;

http://www.aquariumfish.com/aquarium...aid=323&cid=53
&search

For common freshwater species, that table gives you neons at 0.2g and
7cm discus at 19 g. If anyone knows of other resources which report
more adult typical mass values for FW aquarium species, I'd love to see
it. I could bring my fish into work, and weigh each immersed in a fixed
volume in a graduated cylinder (and then weigh the water afterwards to
calculate their mass), but I'd rather save them the stress of such a
trip.

Even after all that, metabolic rate doesn't scale directly with mass of
the fish, but this would be a step in a more accurate direction.

DaveZ
Atom Weaver

As you said, "water surface area of the tank (which is a
more measurable equivalent to oxygen transfer rate)". Oxygen is one
limiting factor, but this should be determined by the
filtration/oxygenation equipment you have in the tank, not surface area.

Another fish-keeping myth is that "fish grow to the size of the tank".
There is some truth in this, although I haven't figured out the
mechanism yet. Perhaps the water quality determins the size of the fish
and as the fish grow too large for the tank/filtration system.
Consequently there is a higher level of nitrite or some other factor
that slows the growth of the fish.

In any case, if you put in a filtration/oxygenation system four times
the recomended size, you can support more fish and your fish will grow
faster.

In other words, your recomendations for rules of fish stocking needs to
take into account factors such as water flow rates, filtration
effectiveness and oxygenation.

On the topic of measuring fish, I always have trouble with the method
you mentioned. I find it is easier and more accurate to measure the
length of the fish and the estimate its mass by interpolation. But
then, I'm a bit of a klutz and my students are even worse. (I first
discovered the effect of incorrect filter sizes on growth rates when I
disassembled the tanks we had used for a growth rate experiment that
failed only to find that the students had mixed up the filters and that
the filter sizes explained the strange results).

A new tank without cycling
 

atomweaver wrote:

Zëbulon wrote in
:


"nut" wrote in message
. ..

Zëbulon wrote:

"Tynk" wrote in message
legroups.com...

You cannot set such a vague "rule" when there are way too many
variables when it comes to stocking a fish...much more than it's
size in inches.

======================
Such as the fact a 1" goldfish passes a lot more waste than a 1"
guppy.

The rule was for tropical fish, not coldwater.

=================
This is true but how many newbies know that? They come here all the
time asking about putting tropicals with goldfish. Some people keep
them together successfully.

Also, some tropicals have a lot more bulk per inch than others.


It would be good to have something a little more accurate than the inch
per gallon guide. In one article I read, they made the excellent
suggestion that the "real" main limiting factors for an aquarium are
mass of fish as adults vs. water surface area of the tank (which is a
more measurable equivalent to oxygen transfer rate), with different
stocking ratios for Fresh, brackish, salt, (and warm and cold) waters.

You could further modify this by multiplier factors considering things
like whether additional oxygenation/waste management is available
(airstone, planted tank etc), or fractional multipliers for if you're
keeping only carnivorous fish (more waste). The main advantage is that
you get a better feel for the differences in body types. The drawback
is that I haven't found many sources which report average/typical adult
fish mass. This is one of them;

http://www.aquariumfish.com/aquarium...aid=323&cid=53
&search

For common freshwater species, that table gives you neons at 0.2g and
7cm discus at 19 g. If anyone knows of other resources which report
more adult typical mass values for FW aquarium species, I'd love to see
it. I could bring my fish into work, and weigh each immersed in a fixed
volume in a graduated cylinder (and then weigh the water afterwards to
calculate their mass), but I'd rather save them the stress of such a
trip.

Even after all that, metabolic rate doesn't scale directly with mass of
the fish, but this would be a step in a more accurate direction.

DaveZ
Atom Weaver
One other factor affecting the bio mass that can be supported in a tank
is the feeding habits of the owners. If you overfeed your fish you can
have less fish in your tank. If you underfeed them, you can have more
fish. (Unless they die of starvation).

A new tank without cycling
 

Jim Morcombe wrote:

atomweaver wrote:
Zëbulon wrote in
:


"nut" wrote in message
...

Zëbulon wrote:

"Tynk" wrote in message
glegroups.com...

You cannot set such a vague "rule" when there are way too many
variables when it comes to stocking a fish...much more than it's
size in inches.

======================
Such as the fact a 1" goldfish passes a lot more waste than a 1"
guppy.

The rule was for tropical fish, not coldwater.

=================
This is true but how many newbies know that? They come here all the
time asking about putting tropicals with goldfish. Some people keep
them together successfully.

Also, some tropicals have a lot more bulk per inch than others.


It would be good to have something a little more accurate than the inch
per gallon guide. In one article I read, they made the excellent
suggestion that the "real" main limiting factors for an aquarium are
mass of fish as adults vs. water surface area of the tank (which is a
more measurable equivalent to oxygen transfer rate), with different
stocking ratios for Fresh, brackish, salt, (and warm and cold) waters.

You could further modify this by multiplier factors considering things
like whether additional oxygenation/waste management is available
(airstone, planted tank etc), or fractional multipliers for if you're
keeping only carnivorous fish (more waste). The main advantage is that
you get a better feel for the differences in body types. The drawback
is that I haven't found many sources which report average/typical adult
fish mass. This is one of them;

http://www.aquariumfish.com/aquarium...aid=323&cid=53
&search

For common freshwater species, that table gives you neons at 0.2g and
7cm discus at 19 g. If anyone knows of other resources which report
more adult typical mass values for FW aquarium species, I'd love to see
it. I could bring my fish into work, and weigh each immersed in a fixed
volume in a graduated cylinder (and then weigh the water afterwards to
calculate their mass), but I'd rather save them the stress of such a
trip.

Even after all that, metabolic rate doesn't scale directly with mass of
the fish, but this would be a step in a more accurate direction.

DaveZ
Atom Weaver

As you said, "water surface area of the tank (which is a
more measurable equivalent to oxygen transfer rate)". Oxygen is one
limiting factor, but this should be determined by the
filtration/oxygenation equipment you have in the tank, not surface area.

Yeah. I don't think surface area is a big factor if you have circulation and
are moving that surface.

Another fish-keeping myth is that "fish grow to the size of the tank".
There is some truth in this, although I haven't figured out the
mechanism yet. Perhaps the water quality determins the size of the fish
and as the fish grow too large for the tank/filtration system.
Consequently there is a higher level of nitrite or some other factor
that slows the growth of the fish.

What happens is that fish grow normally in good conditions and they grow
poorly in poor conditions. Once the various N levels rise, even if its just
very high NO3, then the fish will not grow well. And there are other
toxins, heavy metals, hormones and the rest that will make conditions poor.
So fish will often seem to 'grow to the size of the tank' but what it means
is that the fish are in poor conditions and not healthy.

In any case, if you put in a filtration/oxygenation system four times
the recomended size, you can support more fish and your fish will grow
faster.

Well, for goldfish you need about 4x anyway. The filtration certainly helps.
You keep the toxin levels down, esp NH3 and NO2, and the fish will do
better. You will still need to remove the NO3 and other toxins with plants
and water changes. With a highly overstocked tank you are going to need
water changes very often to keep conditions from becoming poor.

In other words, your recomendations for rules of fish stocking needs to
take into account factors such as water flow rates, filtration
effectiveness and oxygenation.

Yes, I'd agree with that. It pays not to push things too far as maintenance
becomes harder and there is more risk or a sudden catastrophic failure in
the balance.

On the topic of measuring fish, I always have trouble with the method
you mentioned. I find it is easier and more accurate to measure the
length of the fish and the estimate its mass by interpolation. But
then, I'm a bit of a klutz and my students are even worse. (I first
discovered the effect of incorrect filter sizes on growth rates when I
disassembled the tanks we had used for a growth rate experiment that
failed only to find that the students had mixed up the filters and that
the filter sizes explained the strange results).

Stocking is a hard one. It becomes a feel rather than a calculation. Water
parameters and slow stocking is a good way to feel your way into a tank.

A new tank without cycling
 

Jim Morcombe wrote:

atomweaver wrote:

Zëbulon wrote in
:


"nut" wrote in message
...

Zëbulon wrote:

"Tynk" wrote in message
glegroups.com...

You cannot set such a vague "rule" when there are way too many
variables when it comes to stocking a fish...much more than it's
size in inches.

======================
Such as the fact a 1" goldfish passes a lot more waste than a 1"
guppy.

The rule was for tropical fish, not coldwater.

=================
This is true but how many newbies know that? They come here all the
time asking about putting tropicals with goldfish. Some people keep
them together successfully.

Also, some tropicals have a lot more bulk per inch than others.


It would be good to have something a little more accurate than the inch
per gallon guide. In one article I read, they made the excellent
suggestion that the "real" main limiting factors for an aquarium are
mass of fish as adults vs. water surface area of the tank (which is a
more measurable equivalent to oxygen transfer rate), with different
stocking ratios for Fresh, brackish, salt, (and warm and cold) waters.

You could further modify this by multiplier factors considering things
like whether additional oxygenation/waste management is available
(airstone, planted tank etc), or fractional multipliers for if you're
keeping only carnivorous fish (more waste). The main advantage is that
you get a better feel for the differences in body types. The drawback
is that I haven't found many sources which report average/typical adult
fish mass. This is one of them;

http://www.aquariumfish.com/aquarium...aid=323&cid=53
&search

For common freshwater species, that table gives you neons at 0.2g and
7cm discus at 19 g. If anyone knows of other resources which report
more adult typical mass values for FW aquarium species, I'd love to see
it. I could bring my fish into work, and weigh each immersed in a fixed
volume in a graduated cylinder (and then weigh the water afterwards to
calculate their mass), but I'd rather save them the stress of such a
trip.

Even after all that, metabolic rate doesn't scale directly with mass of
the fish, but this would be a step in a more accurate direction.

DaveZ
Atom Weaver
One other factor affecting the bio mass that can be supported in a tank
is the feeding habits of the owners. If you overfeed your fish you can
have less fish in your tank. If you underfeed them, you can have more
fish. (Unless they die of starvation).

I prefer to overfeed rather than underfeed. That way I push the tank past
the stocking level if you know what I mean. That way I'll see any problem
before the tank is overstocked, and then I can cut back feed, let the tank
settle, and then work out how to fix the problem if it needs fixing - ie
plants, more filtration, less fish, etc.

A new tank without cycling
 

Jim Morcombe wrote:
As you said, "water surface area of the tank (which is a
more measurable equivalent to oxygen transfer rate)". Oxygen is one
limiting factor, but this should be determined by the
filtration/oxygenation equipment you have in the tank, not surface area.


I have found a combination of filtration (type of filtration also makes
a difference), circulation, AND surface are make a difference. As an
example, there were these tall narrow in diameter bullet shaped
aquariums that were popular in the early 1980s, many of my clients
purchased them (not from me, I did not sell them). I installed
comparable filters, air pumps, ECT., yet the capacity of these
aquariums were not as high as the more standard rectangular aquariums I
maintained (as measured by ammonia spikes, nitrites, nitrates,
dissolved oxygen and most importantly, general fish health and
longevity.


Another fish-keeping myth is that "fish grow to the size of the tank".
There is some truth in this, although I haven't figured out the
mechanism yet. Perhaps the water quality determins the size of the fish
and as the fish grow too large for the tank/filtration system.
Consequently there is a higher level of nitrite or some other factor
that slows the growth of the fish.

As you stated, I have found many mechanisms here, nitrates (not
nitrites) has an effect on growth of fish. I have not conducted any
serious tests here, but you raise some interesting points. For instance
in the case of goldfish in under sized aquariums (which is all too
common for GF), I have noticed in a few tanks (not many as I have not
purposefully tried to push the over crowding rule), that goldfish will
grow quickly in very healthy, well filtered, excellent water parameter
aquariums vs. clients who have called me out to small aquariums with
poor conditions that are crowded with GF where the customers has argued
that they have had these fish for "years" in the small aquarium, yet
these fish are small. Of coarse the term here is stunting and these
fish rarely thrive and live as long.

In any case, if you put in a filtration/oxygenation system four times
the recomended size, you can support more fish and your fish will grow
faster.

In other words, your recomendations for rules of fish stocking needs to
take into account factors such as water flow rates, filtration
effectiveness and oxygenation.

I agree, you raise many good points, but surface are is still a major
factor. I mention all these factors in my basic FW aquarium article:
http://www.americanaquariumproducts....rinciples.html

Carl

A new tank without cycling
 

Jim Morcombe wrote in
:

atomweaver wrote:


It would be good to have something a little more accurate than the
inch per gallon guide. In one article I read, they made the
excellent suggestion that the "real" main limiting factors for an
aquarium are mass of fish as adults vs. water surface area of the
tank (which is a more measurable equivalent to oxygen transfer rate),
with different stocking ratios for Fresh, brackish, salt, (and warm
and cold) waters.

You could further modify this by multiplier factors considering
things
like whether additional oxygenation/waste management is available
(airstone, planted tank etc), or fractional multipliers for if you're
keeping only carnivorous fish (more waste). The main advantage is
that you get a better feel for the differences in body types. The
drawback is that I haven't found many sources which report
average/typical adult fish mass. This is one of them;

http://www.aquariumfish.com/aquarium...aid=323&cid=53
&search

For common freshwater species, that table gives you neons at 0.2g and
7cm discus at 19 g. If anyone knows of other resources which report
more adult typical mass values for FW aquarium species, I'd love to
see it. I could bring my fish into work, and weigh each immersed in
a fixed volume in a graduated cylinder (and then weigh the water
afterwards to calculate their mass), but I'd rather save them the
stress of such a trip.

Even after all that, metabolic rate doesn't scale directly with mass
of the fish, but this would be a step in a more accurate direction.

DaveZ
Atom Weaver

As you said, "water surface area of the tank (which is a
more measurable equivalent to oxygen transfer rate)". Oxygen is one
limiting factor, but this should be determined by the
filtration/oxygenation equipment you have in the tank, not surface
area.

Hm. Really? I knew that aggressive oxygenation could increase stocking
levels, but I've never heard the claim before that filtration determines
oxygenation levels (determines, as in, "is the primary/key factor"). I
suppose a turbulent flow or any other filtration method that increases the
air-water interface would alter oxygen transfer, but thats just another way
of raising water surface area... If it really was a big factor, one would
expect that sumps would be more popular in FW setups.
I think if you're trying to develop a "rule of thumb" which is improved
over the "inch per gallon" rule system size has to be taken into account
somehow. Trading filtration/oxygenation capacity for surface area (and
indirectly, tank size) doesn't seem like a wise trade off.

In any case, if you put in a filtration/oxygenation system four times
the recomended size, you can support more fish and your fish will grow
faster.

In other words, your recomendations for rules of fish stocking needs
to take into account factors such as water flow rates, filtration
effectiveness and oxygenation.


Right. Thats what I was getting at, when I wrote:

"You could further modify this by multiplier factors considering things
like whether additional oxygenation/waste management is available
(airstone, planted tank etc), or fractional multipliers for if you're
keeping only carnivorous fish (more waste)."

So, you develop a base stocking guideline which says (and these numbers are
totally arbitrary):

2.5 g of adult fish mass per 10 cm^2 of surface area (assumes a HOB
filter with low turbulence, freshwater, unplanted, 76-78 degF).

Airstone mulitplier is 1.3 (if airstone is properly sized to the tank)
Carnivore/messy eater multiplier is 0.8
Bio wheel multiplier is 1.05
Over feeding multiplier is 0.75
Heavy water change (75%/week) multiplier is 1.2
High temp multiplier is X
Low temp multiplier is Y
etc.

Again, I'm pulling numbers out of thin air, just to demonstrate how the
guideline would work. As I write out the multiplier list, it strikes me
that the more multipliers you apply, the less accurate the guideline would
become.

On the topic of measuring fish, I always have trouble with the method
you mentioned. I find it is easier and more accurate to measure the
length of the fish and the estimate its mass by interpolation. But
then, I'm a bit of a klutz and my students are even worse. (I first
discovered the effect of incorrect filter sizes on growth rates when I
disassembled the tanks we had used for a growth rate experiment that
failed only to find that the students had mixed up the filters and
that the filter sizes explained the strange results).

Yeah, I guess I think of the tools I use at work first, rather than trust
to my capabilities of interpolation. I measure polymer densities by the
Eureka-plus-Scale method, and it struck me as a way to do things with fish,
too. :) Something tells me the fish would be less co-operative than the
plastic. Heh.

Thanks for the reply.

DaveZ
Atom Weaver