I'm doing fish research at university with my professor, and we have 9 tanks of goldfish at school. We are having a small problem with some of the tanks.
Here are some constants, first. They are all glass 10g tanks, they all have HOB filters, they all have no substrate at all, all are on a 12h photoperiod, all have 6 goldfish, all have been running the same length of time, all have thermometers.
We had a misunderstanding and the filter-pads did not get replaced (but they were cleaned every week) for a few months.
Three of the tanks are very cloudy. We've tried everything to get rid of the cloudy water. We've tried the Clarity water clearing solution. We've tried lowering the pH (pH of all tanks is > 7.6) and then adding back in electrolytes.
For maintanence, we do weekly water changes (25%-40% of water) and clean the filters. With the water changes I use a shake-activated (name?) gravel siphoner to get all the waste out of the tank while getting the water out. We fill it with water that has been sitting in buckets for a week being airated(sp?). After each water change I add 5mL of Stress Coat and Stress Zyme.
Today I did a 50% water change on the tanks, and even went a little futher on the tanks that were extra-cloudy. Does anyone know what the cause for cloudy water could be? The water is *very* cloudy in the cloudy tanks, it almost looks like muddy water (think Flourite!)
Should we try more frequent water changes on the cloudy tanks? We hate to keep adding chemicals.
I appreciate any suggestions. Thank you!