Fish died

Question
My son had a betta and the last time i cleaned out it was nastier than usual.  I could not get that smell no matter how much soap and water i used.  So i filled it up and added a touch of pinesol and let it sit for a little while. I rinsed it out for a good half hour and filled it with fresh water and added the water conditioner.  The next day his fish was dead and the water smell a little like pinesol.  I got him another fish, a black moor and i cleaned the tank once again but it had a whitish cloudy substance on the bottom of the tank that wouldnt come off.  Then the next day that fish was dead as well.  I take it that i shouldnt have used pinesol to disinfect it. Need some advice so i dont kill any more fish, should i just get another tank?

Answer
Sorry about your loss, Jennifer.

Pine Sol has 3 components that are toxic to fish (and humans).

If it's completely rinsed away, there's no problem. Unfortunately they can be absorbed into parts of the aquarium. If it's a glass aquarium it can be absorbed into the silicone sealant that bonds the glass to the frame, if it's a plastic aquarium, it can be absorbed into the plastic. If there are decorative features like plastic plants in the tank, they can absorb chemicals too.

You could soak the tank in water for a couple of weeks, changing the water every day, then let it stand dry in the sun for a few days, but if it's not too big a deal, getting a new tank might be easier.

Remember too, that Bettas don't require aeration in a tank and usually Black Moors do. That might be part of the problem too.

Don't forget when changing water that the new water needs to be very similar to the old water - except cleaner. Same temperature, pH, and minerals. You mentioned that you used "water conditioner" - hopefully, that was something that also eliminates chlorine from the tap water.

Good luck,

Chris Bushman
North Hollywood, California