When I was a kid my 20 gallon tank developed a bad case of grey cloudy water. I knew what caused it - suspended bacteria - but I couldn't afford a filter, so I went to a local pond, caught a two inch fresh water mussel, and put it into the aquarium.
In three days the aquarium was crystal clear. It was also a mess, because the mussel travelled constantly and uprooted plants as he went. I returned it to the pond.
BTW, many of the fish in that pond had small dark cysts on their bodies, which I assumed were one of the life stages of the mussels. They fish didn't seemed to be bothered by it.
Bill
In three days the aquarium was crystal clear. It was also a mess, because the mussel travelled constantly and uprooted plants as he went. I returned it to the pond.
BTW, many of the fish in that pond had small dark cysts on their bodies, which I assumed were one of the life stages of the mussels. They fish didn't seemed to be bothered by it.
Bill
