after changing water problems

[Lizy33]

My fishes were swimming normal but after I changed 40% or so of the water they've been swimming on top and seem like they are out of oxygen gasping for air. should I add more conditioning? Change more water? I don't know what to do. I also cleaned the filter when i changed the water. Thank you!

 

[Byron]

There are a couple possibles. First, are you certain you added conditioner, sufficient for the 40% fresh water? It is not necessary to add more than for the volume replaced, but it is important to add that level. Chlorine and chloramine (if also present in your tap water) are highly toxic and burn the gills, so fish will remain gasping at the surface.

Another possible is a vast change in parameters (pH primarily here) or sudden ammonia or nitrite. The latter two can occur from tap water. Ammonia can also occur if the pH of the tank was below 7 prior to the change, and rose above 7 following the change. This latter is usually only associated with massive water changes in tanks that have gone without sufficient changes and built up acidity. The harmless ammonium in acidic water changes to toxic ammonia in basic (pH above 7) water.

Another possible is some toxin in the water, either in the tap water itself or introduced during the change from pails, hoses, or people.

If you have test kits, you could test for pH, ammonia, nitrite and nitrate, all or whichever you have. And add more conditioner if you think it was insufficient or forgotten.

 

[Lizy33]

There are a couple possibles. First, are you certain you added conditioner, sufficient for the 40% fresh water? It is not necessary to add more than for the volume replaced, but it is important to add that level. Chlorine and chloramine (if also present in your tap water) are highly toxic and burn the gills, so fish will remain gasping at the surface.

Another possible is a vast change in parameters (pH primarily here) or sudden ammonia or nitrite. The latter two can occur from tap water. Ammonia can also occur if the pH of the tank was below 7 prior to the change, and rose above 7 following the change. This latter is usually only associated with massive water changes in tanks that have gone without sufficient changes and built up acidity. The harmless ammonium in acidic water changes to toxic ammonia in basic (pH above 7) water.

Another possible is some toxin in the water, either in the tap water itself or introduced during the change from pails, hoses, or people.

If you have test kits, you could test for pH, ammonia, nitrite and nitrate, all or whichever you have. And add more conditioner if you think it was insufficient or forgotten.

Thank you.