You are already talking about restocking and haven't a clue what went wrong. If I am not mistaken you killed some fish a while back by using too much Aquaclear. You use a "jar", but don't say what size or how you measure the water and you need some type of thermometer. (Cloudy water made me think it was too warm) I can't explain this, Fishman, but my tanks are within two degrees of one another yet when I stick my fingers in my brain senses them way different so I can't rely on the touch system. Another thing - did you get the water from the same faucet? Some people on wells put in water softeners, but don't use it on all their faucets. You also mention "top off" - I have been under the impression that wasn't the thing to do - if your water is low, you change some. When was the last time you did a water change? If it was more than a couple of weeks maybe there was a drastic difference between the tank & well water. I can't help but feel your problem was either a miscalculation of Aquaclear or temp. 25% is 5 gallons or 20 quarts depending in the size of the jar you use. Anyway, before you even think about stock, you need to own the test kit, a thermometer, a suitable method to vacuum and a clean bucket that is only yours.