Unexplained Fish Deaths

[Kissifish]

Need some help, as I haven't encountered this problem before.

The past two times I have done a partial water change (every week), I have had major fish deaths. The first time I thought it was due age of fish (Otos that I had had for over two years). But in the following days, I lost 4 Otos, 3 Neon Tetras, and a Glass Cat (all who were previously healthy). This week, within 24 hours after a water change, so far, I have lost another Glass Cat.

Each time all water parameters have checked out as normal for these fish, water temperature was the same as what I took out, and was treated to dechlorinate.

The only thing different in the tank each time was a growth of green algae on the rocks.

The water department has been flushing the water lines lately. Would this stir up anything in the water that could poison the fish (not to mention what it could do to us!)? Or would the algae be giving off some chemical that could harm them?

Need help soon before I have no fish left! Definitely don't want to add more until I know what's going on. In addition, this is a 10 gallon tank that has been up and running for about 6 years now with no problems. Last year we added rocks which we scrubbed and soaked and tested with vinegar, and some driftwood from a freshwater pond (also cleaned, soaked, and tested).

Any clues? Hope so. Cause I'm clueless.

 

[Guppylover]

It sound like they water you are adding to your tank after a water change seem to be causing this... you do add water conditioning to the water before you add it to your tank?
Mabye if the water you use to do a water change is causing this try to boil the water first, let it cool down then add it to the aquarium.

 

[FishDan]

This time of year many water companies add extra chemicls to the water to keep things clean and clear. Both for us and the pipes. It is possible that your WC is adding more chemicals or different ones to treat the water. What conditioner do you use? A chamical that is starting to be used more frequently is chloramine, which does not gas out of water like chlorine. And not all dechlorinators deal with chloramines. The added or additional chemicals from your water may be causing the trouble. You can call your WC and see if they are adding anything different to the water. Also, do you have any symptoms you could share?

\Dan

 

[Logitech]

Yeah, it could be the water you are putting into your tank after water changes. You should definitley condition your water before putting it in your tank. Try that and see if your fish live.