my tests say I don't need water changes

Hey all,

I'm a first time poster. I did a quick search on my post topic, and
didn't find answers to my question. If my question's been covered
before, please don't reply - I'll look it up myself. Thanks (just
trying to avoid annoying people, but maybe I have already!).

The scenario:

29 gallon aquarium
two adult cichlids - Pseudotropheus Zebra and a Jewel cichlid
(hemichromus bimiculatus, I believe).
I feed them as much as they can eat in about 3 minutes about once a
day.
Marineland Penguin 170 filter with a bio-wheel
No undergravel filter or additional filtration of any kind.
I have about 2 inches of rock substrate (about 7mm in diam - pretty
big)
I've been doing 15% water changes every week (5 gal bucket). I vacuum
the substrate of excess food, etc. every other week.

Out of curiosity, I recently bought an Aquarium Pharmaceuticals
Freshwater Master Water Test Kit. I've been using it weekly for just
over a month. Every week, my water chemistry tests at: 8.0 pH, between
8 and 10 deg General Hardness, 0ppm ammonia, and 0ppm nitrites. I
realize that this is a good thing!

I have been told for years that aquarists do 25% weekly water changes
in order to clear potential toxic waste chemicals out of the aquarium.

The question/s:

If my chemistry is consistently perfect (IMHO!), why should I do
weekly water changes?

Are there other chemicals that I need to clean out that I'm not
testing for?

Is there something magical about fresh water that keeps my cichlids
healthier than they otherwise might be? If I were to not change the
water, might they succumb to other non-nitrogen cycle related
illnesses?

Lastly, why might my chemistry be so good? I'm barely trying! I have
cichlids, which are usually dirty eaters, no UGF, one filter (whose
carbon I have only changed once in 9 months), and I only do 15%
changes instead of 25%. Not to be naive, but could it be the
bio-wheel? Maybe I don't feed my fish as much as most people.

Thanks for your thoughts,

Dave T.
davetrendler at juno nospam dot com

HumbuckerDaveT. wrote:

I'm a first time poster. I did a quick search on my post topic, and
didn't find answers to my question. If my question's been covered
before, please don't reply - I'll look it up myself. Thanks (just
trying to avoid annoying people, but maybe I have already!).

Welcome.

I feed them as much as they can eat in about 3 minutes about once a
day.

When you feed them, you are adding nitrogen to the system in the form of
protein in the food. This nitrogen must be exported by water changes or
some other means. You are feeding a proper amount.

Marineland Penguin 170 filter with a bio-wheel
No undergravel filter or additional filtration of any kind.

This is a fine filter with both mechanical and biological filtration.

I have about 2 inches of rock substrate (about 7mm in diam - pretty
big) I've been doing 15% water changes every week (5 gal bucket). I vacuum
the substrate of excess food, etc. every other week.

This is good.

Out of curiosity, I recently bought an Aquarium Pharmaceuticals
Freshwater Master Water Test Kit. I've been using it weekly for just
over a month. Every week, my water chemistry tests at: 8.0 pH, between
8 and 10 deg General Hardness, 0ppm ammonia, and 0ppm nitrites. I
realize that this is a good thing!

A good thing indeed.

I have been told for years that aquarists do 25% weekly water changes
in order to clear potential toxic waste chemicals out of the aquarium.
The question/s:
If my chemistry is consistently perfect (IMHO!), why should I do
weekly water changes?
Are there other chemicals that I need to clean out that I'm not
testing for?

Steady pH and hardness as well as 0 NH3 (ammonia) & 0 NO2- (nitrite) are
all very good ! However you must also test for NO3- (nitrate) !

All that nitrogen (from the daily feedings) gets efficiently oxidized by
the bacteria on your biowheel. NH3 & NO2- are the really toxic ones and
your biofilter is very good at converting these to NO3-.

Your fish excrete excess nitrogen from their diet in the form of NH3.

This ammonia gets converted to NO2- and then to NO3- by your biowheel.

NO3- is not AS toxic, but you want to keep the level of nitrate below
20-40ppm.

I would suggest that you acquire a good nitrate test kit. Once your tank
is cycled (ie 0 NH3 & 0 NO2-), the nitrate kit is the most useful--because
it tells you how often to change the water.

The golden rule of water changes is that you do them often enough to keep
the nitrate (NO3-) concentration in the range that your fish thrive in
(generally 20-40ppm).

LaMotte makes expensive, but highly accurate and reproducible test kits.
They do offer cheaper refills on the reagent part of the kit.

No matter what kit you use, I'll bet next months rent that your nitrate is
pretty high.

Is there something magical about fresh water that keeps my cichlids
healthier than they otherwise might be? If I were to not change the
water, might they succumb to other non-nitrogen cycle related
illnesses?

See above. They can be stressed by high nitrate levels.

Lastly, why might my chemistry be so good? I'm barely trying! I have
cichlids, which are usually dirty eaters, no UGF, one filter (whose
carbon I have only changed once in 9 months), and I only do 15%
changes instead of 25%. Not to be naive, but could it be the
bio-wheel? Maybe I don't feed my fish as much as most people.

It sounds like you have a 30-40 gallon tank and it seems lightly
stocked--this is good. Avoiding overfeeding is also good. These contribute
to good water chemistry.

Test your nitrate and do more water changes if the levels are above
40ppm. You can empirically determine how often, and what percent to change
to keep nitrates to a good level (20-40ppm). Then you can settle into a
routine and not worry about stuff--always knowing your fish are happy.

Also--your carbon absorbed whatever nasty stuff it could in the first
month or 2 of its life. Now it is slowly leaching this brew back into your
water. Do yourself (& fish) a favor and toss it for good. It is much
better (& cheaper!) to rely on water changes diluting bad things than
carbon. Replace it with a sponge or some other mechanical filter and
clean it for free more often.

Cheers--Jeff Dantzler

P.S. There is more on this in the archives.
Search on 'water changes nitrate nitrogen'.

You don't have much of a Bio load with 2 fish in a 29g tank... Pretty self
explanitory I think... I do consistant 10% water changes in my 55's The
one 55 is not over loaded with 5 residents while the other has about 30
adult residents... Once the Bio filter is in full swing and can keep up, (
as it can in your case with two adults ) the water parameters stay
consistant, where as my Community 55 requires a lot of attention.. You clean
the gravel for excessive "garbage" and this helps.. Do I think the Bio wheel
may have helped? I can't tell you any lies, I don't know, as I don't use
these filters as I think the media and cartridges are excessively priced.. I
have a preference for the Aqua Clears myself, and perhaps I may convert the
tanks all to Canisters once I find out how the Eheim fully operates under a
heavy load.. I don't use UGF's, nor do I like to rely on using carbon (
seems to help with the promotion of HTH in New world Cic's ). The reason to
keep performing weekly changes is simply as well, would you like to live in
a septic tank? Granted the Bio bugs do break down the crap and corruption, I
think you see the point.. And hey.. Happy Fish keeping..

Tim...
"HumbuckerDaveT." wrote in message
m...
Hey all,

I'm a first time poster. I did a quick search on my post topic, and
didn't find answers to my question. If my question's been covered
before, please don't reply - I'll look it up myself. Thanks (just
trying to avoid annoying people, but maybe I have already!).

The scenario:

29 gallon aquarium
two adult cichlids - Pseudotropheus Zebra and a Jewel cichlid
(hemichromus bimiculatus, I believe).
I feed them as much as they can eat in about 3 minutes about once a
day.
Marineland Penguin 170 filter with a bio-wheel
No undergravel filter or additional filtration of any kind.
I have about 2 inches of rock substrate (about 7mm in diam - pretty
big)
I've been doing 15% water changes every week (5 gal bucket). I vacuum
the substrate of excess food, etc. every other week.

Out of curiosity, I recently bought an Aquarium Pharmaceuticals
Freshwater Master Water Test Kit. I've been using it weekly for just
over a month. Every week, my water chemistry tests at: 8.0 pH, between
8 and 10 deg General Hardness, 0ppm ammonia, and 0ppm nitrites. I
realize that this is a good thing!

I have been told for years that aquarists do 25% weekly water changes
in order to clear potential toxic waste chemicals out of the aquarium.

The question/s:

If my chemistry is consistently perfect (IMHO!), why should I do
weekly water changes?

Are there other chemicals that I need to clean out that I'm not
testing for?

Is there something magical about fresh water that keeps my cichlids
healthier than they otherwise might be? If I were to not change the
water, might they succumb to other non-nitrogen cycle related
illnesses?

Lastly, why might my chemistry be so good? I'm barely trying! I have
cichlids, which are usually dirty eaters, no UGF, one filter (whose
carbon I have only changed once in 9 months), and I only do 15%
changes instead of 25%. Not to be naive, but could it be the
bio-wheel? Maybe I don't feed my fish as much as most people.

Thanks for your thoughts,

Dave T.
davetrendler at juno nospam dot com

One further bit of advice to follow up to Jeff's excellent post... test
your tap water for nitrates as well, especially if you live in an
agricultural area. While USA law (and Canadian too I think) says that tap
water shouldn't exceed 10ppm nitrate, some communities (such as mine)
still have tap water that averages 20ppm nitrate because of agricultural
runoff. In such cases, you will need to alter the standard maintenance
routines. In my case, I use plants in all my tanks with sufficient light
and nutrients for them to thrive, only sweat the algae when it competes
for the plants so much that it starts killing the plants off and make more
frequent but smaller water changes. This has resulted in my tanks having
less nitrates than my tap water usually, as the plants and algae appear to
be metabolizing the nitrates faster than I or my fish add them.

On Sat, 14 Feb 2004 09:21:09 +0000 (UTC), Cichlidiot
wrote:

.... While USA law (and Canadian too I think) says that tap
water shouldn't exceed 10ppm nitrate

In Canada there may be federal guidelines, but it's the province's
health regulators that specify the nitrate content.

For example, in New Brunswick, Nitrate will not exceed 10 ppm from a
municipal water supply, or else it's deemed unfit for drinking (ok,
that was a bit simplistic)

HumbuckerDaveT. wrote:
Hey all,

major snipage

Read the thread intitled "Old Tank syndrom conundrum...long" in
rec.aquaria.freshwater.misc and you will find out what can happen.
Granted, with your light bio load, it will take a long time...

Here's a link that will probably give you other search ideas:
http://www.bestfish.com/oldtank.html

--
TF

Put my handle in front of the domain name to email.

Hey all,

Thanks for your excellent thoughts!

I bought a nitrate test kit as Mr. Dantzler suggested. He said he
would "bet next months rent that your nitrate is pretty high." Had we
been gambling, I'd owe Jeff some money. My nitrates were at 20ppm. Not
super high, but high enough for me to change more water more often.

Thanks to Cichlidiot - I'll test my tap water for nitrates a few times
a year, more often during "fertilization" season in Colorado, and see
how much nitrogen it's contributing to the tank.

I've been moving slowly into adding plants to my tank, so hopefully
that will help to fix some nitrogen as well.

Thanks also to Jeff for the excellent observation that old carbon will
leak its contents into water that is cleaner than the carbon. I've
replaced my very old carbon filter. I'll probably dump it for good as
Jeff suggested, once I run out of my inventory.

Time for more and larger water changes and preventing Old Tank
Syndrome!

Thanks again,
Dave