Fish and temperature change

It's a commonly accepted rule that fish need to slowly adjust to
changes in water temperature and this is one of the reasons why bagged
fish are supposed to float for a while before being introduced into a
new body of water. I'm starting to think that this temperature
adjustment rule is a whole lot of bunk. One of the things I've noticed
about pondkeeping is that different areas of a pond can have radically
different temperatures, and that goes double for ponds without any
circulation. Shallow areas without much vegetation are significantly
warmer than areas just 2' in depth, and this situation must be the norm
since one of the tips to trigger faster growth of water lilies is to
lift the pots near the surface because the water is warmer! Even with
these big temperature differences in portions of a pond goldfish and
koi will peacefully cruise from cool areas to warm areas without
showing any concern at all. How can this be if fish are really as
sensitive to temperature changes as we've been lead to believe?

Does it have to do with the fact that a fish can return to water that
it's adjusted to if it finds a new pocket of water that's too
uncomfortable? If so, sometimes it takes a long, long time for them to
become uncomfortable. Is it possible that this rule is mainly for
aquarium fish where the entire body of water is likely to be the exact
same temperature and a newly introduced fish wouldn't be able to find
water of its body temperature?

"scs0" wrote in message
oups.com...
It's a commonly accepted rule that fish need to slowly adjust to
changes in water temperature and this is one of the reasons why bagged
fish are supposed to float for a while before being introduced into a
new body of water. I'm starting to think that this temperature
adjustment rule is a whole lot of bunk.

$$ If the water is only slightly warmer or cooler I haven't found any
problems.
However I did lose some young fry when the temps dropped to near freezing
here for two nights. They were in 30 gallon tubs and probably cooled too
fast once the temps plummeted.

One of the things I've noticed
about pondkeeping is that different areas of a pond can have radically
different temperatures, and that goes double for ponds without any
circulation. Shallow areas without much vegetation are significantly
warmer than areas just 2' in depth, and this situation must be the norm
since one of the tips to trigger faster growth of water lilies is to
lift the pots near the surface because the water is warmer! Even with
these big temperature differences in portions of a pond goldfish and
koi will peacefully cruise from cool areas to warm areas without
showing any concern at all. How can this be if fish are really as
sensitive to temperature changes as we've been lead to believe?

$$ I observe this in my ponds and pools as well. :-) It's much cooler
under the water lilies and in the other, shallower end of the pond exposed
to the sun.

Does it have to do with the fact that a fish can return to water that
it's adjusted to if it finds a new pocket of water that's too
uncomfortable? If so, sometimes it takes a long, long time for them to
become uncomfortable. Is it possible that this rule is mainly for
aquarium fish where the entire body of water is likely to be the exact
same temperature and a newly introduced fish wouldn't be able to find
water of its body temperature?

$$ I personally would tend to think so.
--
McKoi.... the frugal ponder...
EVERYONE: "Please check people's headers for forgeries
before flushing." :-)
~~~ }((((o ~~~ }{{{{o ~~~ }(((((o

On 16 May 2005 11:18:56 -0700, "scs0" wrote:

It's a commonly accepted rule that fish need to slowly adjust to
changes in water temperature and this is one of the reasons why bagged
fish are supposed to float for a while before being introduced into a
new body of water. I'm starting to think that this temperature
adjustment rule is a whole lot of bunk. One of the things I've noticed
about pondkeeping is that different areas of a pond can have radically
different temperatures, and that goes double for ponds without any
circulation. snip

Not bunk. Fish that are bagged are under a lot of stress, from being
bagged, so you want to remove as many stresses as you physically can, like
letting the "unopened" bag acclimate to the temperature of the quarantine
tank. I go one step further and match my Q-tank's pH to the sellers, and if
the fish has been in the bag long enough to have drop the pH way down, I
lower the pH to 7.0.

If a fish has been in a bag longer than 30 minutes, leave the bag closed
and do not add pond water to the bag. Get the temperatures and pH numbers
similar and lift the fish out of the bag without putting the bag water into
the pond. ~ jan


See my ponds and filter design:
www.jjspond.us

~Keep 'em Wet!~
Tri-Cities WA Zone 7a
To e-mail see website

We always net fish and toss water. Lowers contamination! We do adjust
water by mixing before moving the fish and tossing the water. Our
aquaria sure don't need disease water from a pet store.

Jim

~ jan JJsPond.us wrote:
On 16 May 2005 11:18:56 -0700, "scs0" wrote:


It's a commonly accepted rule that fish need to slowly adjust to
changes in water temperature and this is one of the reasons why bagged
fish are supposed to float for a while before being introduced into a
new body of water. I'm starting to think that this temperature
adjustment rule is a whole lot of bunk. One of the things I've noticed
about pondkeeping is that different areas of a pond can have radically
different temperatures, and that goes double for ponds without any
circulation. snip


Not bunk. Fish that are bagged are under a lot of stress, from being
bagged, so you want to remove as many stresses as you physically can, like
letting the "unopened" bag acclimate to the temperature of the quarantine
tank. I go one step further and match my Q-tank's pH to the sellers, and if
the fish has been in the bag long enough to have drop the pH way down, I
lower the pH to 7.0.

If a fish has been in a bag longer than 30 minutes, leave the bag closed
and do not add pond water to the bag. Get the temperatures and pH numbers
similar and lift the fish out of the bag without putting the bag water into
the pond. ~ jan


See my ponds and filter design:
www.jjspond.us

~Keep 'em Wet!~
Tri-Cities WA Zone 7a
To e-mail see website

"Phyllis and Jim Hurley" wrote in message
.. .
We always net fish and toss water. Lowers contamination! We do adjust
water by mixing before moving the fish and tossing the water. Our
aquaria sure don't need disease water from a pet store.
=======================================
I hope you're using a quarantine tank for at least 14 days. To add new fish
to an established aquarium or pond is really taking a chance.
--
McKoi.... the frugal ponder...
EVERYONE: "Please check people's headers for forgeries
before flushing." :-)
~~~ }((((o ~~~ }{{{{o ~~~ }(((((o

Phyllis and Jim Hurley wrote:
We always net fish and toss water. Lowers contamination! We do adjust
water by mixing before moving the fish and tossing the water. Our
aquaria sure don't need disease water from a pet store.

Jim

If you are going to add water to a fish bag, it's always a good idea to
add an ammonia neutralizer. That way you don't raise the pH and trigger
ammonia toxicity.

My bagged fish get transferred to a covered bowl or bucket with a couple
drops of AmQuel, and then I drip in water until the fish is in about 3/4
Q-tank water. Finally, I net the fish out of the container so that I
don't add store water to the Q-tank.

--
Elaine T __
http://eethomp.com/fish.html '__
rec.aquaria.* FAQ http://faq.thekrib.com

On Mon, 16 May 2005 20:53:56 -0500, Phyllis and Jim Hurley wrote:

We always net fish and toss water. Lowers contamination! We do adjust
water by mixing before moving the fish and tossing the water. Our
aquaria sure don't need disease water from a pet store.

Jim

Mixing is fine, if the fish is purchased locally. If not, if the fish has
been bagged longer than an hour, the water in the bag is loaded with
ammonia that is non-toxic because the pH is very low, due to the Carbon
Dioxide. You add water with a higher pH and the ammonia is now toxic to the
fish. The longer the fish has been bagged the worst this can be. ~ jan


See my ponds and filter design:
www.jjspond.us

~Keep 'em Wet!~
Tri-Cities WA Zone 7a
To e-mail see website

scs0 wrote:

It's a commonly accepted rule that fish need to slowly adjust to
changes in water temperature and this is one of the reasons why bagged
fish are supposed to float for a while before being introduced into a
new body of water. I'm starting to think that this temperature
adjustment rule is a whole lot of bunk.
....
Does it have to do with the fact that a fish can return to water that
it's adjusted to if it finds a new pocket of water that's too
uncomfortable?

I don't know that anybody can really answer that question. The same problem
occurs with species of fish that are caught at great depth. In the
aquarium trade there are African cichlids that are caught at 120' or
deeper, that really need to be "decompressed" as they're brought to the
surface (otherwise they develop swim bladder problems), yet these same fish
are known to come to the surface on their own.

I would think it comes down mostly to the fact that the fish know when they
are approaching the limits of the temperature or pressure change that they
can handle (it probably hurts), but we can't tell the point at which the
change is stressing them too much.
--
derek