Fish gasping at surface after water change

[BDB]

When I do a water change, usually about 30%, the fish (giant danios) spend
the next few hours gasping at the surface. I'm wondering what's causing
this. It's not the temp because I tried using temp adjusted water from
the sink. Could it be chlorine in the water? I didn't try amquel yet.
Or maybe lack of oxygen in the water? I don't have an airstone
running so maybe there isn't much to begin with and the tap water has
even less?

[Nikki Casali]

BDB wrote:

> When I do a water change, usually about 30%, the fish (giant danios) spend
> the next few hours gasping at the surface. I'm wondering what's causing
> this. It's not the temp because I tried using temp adjusted water from
> the sink. Could it be chlorine in the water? I didn't try amquel yet.
> Or maybe lack of oxygen in the water? I don't have an airstone
> running so maybe there isn't much to begin with and the tap water has
> even less?

It could be to do with very high CO2 content and/or lack of oxygen in
your tap water. The next time you change the tank water, try aerating
the change water in a bucket for an hour and add dechlorinator. The
aeration will cause the CO2 or any other noxious gases to dissipate.

Nikki

[Elaine T]

BDB wrote:
> When I do a water change, usually about 30%, the fish (giant danios) spend
> the next few hours gasping at the surface. I'm wondering what's causing
> this. It's not the temp because I tried using temp adjusted water from
> the sink. Could it be chlorine in the water? I didn't try amquel yet.
> Or maybe lack of oxygen in the water? I don't have an airstone
> running so maybe there isn't much to begin with and the tap water has
> even less?

Are you treating the water at all? Chlorine causes gasping, as can
chloramine. You should be able to find out what's in your water from
your local water supply or fish store. It is very important to treat
tap water for chloramine and/or chlorine for water changes as big as 30%
- you can kill your fish.

Tapwater rarely has too little oxygen - the problem is generally too
much dissolved air. Either way, if you pour the water change water into
the tank from a height so that it splashes, you'll equalize the gasses
better.

An airstone is pretty inexpensive peace of mind, especially if your tank
is running warm. Warm water holds considerably less oxygen.

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

[Bill Stock]

"BDB" > wrote in message
...
> When I do a water change, usually about 30%, the fish (giant danios) spend
> the next few hours gasping at the surface. I'm wondering what's causing
> this. It's not the temp because I tried using temp adjusted water from
> the sink. Could it be chlorine in the water? I didn't try amquel yet.
> Or maybe lack of oxygen in the water? I don't have an airstone
> running so maybe there isn't much to begin with and the tap water has
> even less?

My largest Goldfish does this when I change the water, but I've never known
why him and not the others. He had a bad fungus infection a few months back,
so perhaps it's his health or his large size. It's not the temperature
(never changes more than .1) or Chlorine (I treat with Sodium Thiosulphate).
The water does have a lot of disolved gasses though, you can see the 'mist'
when I add the water.

[Ross]

Could it have to do with a change in Osmotic pressure? I read somewhere
else if water changes are done infrequently, that it can cause problems
with a fishes gills.

Ross T

[Derek Benson]

On Thu, 14 Jul 2005 19:05:07 GMT, BDB > wrote:

>When I do a water change, usually about 30%, the fish (giant danios) spend
>the next few hours gasping at the surface. I'm wondering what's causing
>this. It's not the temp because I tried using temp adjusted water from
>the sink. Could it be chlorine in the water? I didn't try amquel yet.
>Or maybe lack of oxygen in the water? I don't have an airstone
>running so maybe there isn't much to begin with and the tap water has
>even less?

Sounds like poisoning to me; either chlorine, chloramine or heavy
metals (copper for example) in your tap water. You should use Amquel
or some other water conditioner which takes care of these three
things.

You don't necessarily need a separate airstone in your tank to be sure
of enough oxygen. What is important is how much water movement you
have at the surface of the water. If you have a cannister filter like
an Eheim, you point the spraybar not down into the water, but at an
angle just under the water surface, so it's blowing the surface water
towards the other side of the tank, creating a lot of surface water
agitation.

-Derek