white dots moving in the bottom my aquarium

Question
I was wondering about my fish tank, i have these little white dots moving around on the bottom of the fish tank, i have no idea of what they are. I have a 46 gallon tank, the types of fish in the tank are 2 black and grey tetras, 2 red and black tetras, 2 gouramis, peach colored algea eater, 1 small frog. I feed them shrimp pellets sometimes and tetramin tropical flakes everyday, the ph of the tank is 6.8, and the water is cloudy(I think I need to change the filter). Could you please tell me what these little dots moving around the bottom of the tank, some are also under the rocks.
Thanks Ian  

Answer
Hi,
I think it is some sort of parasite, but without a picture or a very detailed description it is impossible to tell. Most parasites are harmless, but if you see small white flecks around the fish's fins and body, it is white spot.
Do 30 percent water changes twice a week until it has gone away, then resume back to once a week. Only rinse half the filter in tank water every month or so. Do not replace any of the filter media until it is physically falling apart.
I'd recommend buying a few more Tetras, as they prefer to be in groups of 6 or more.
If you could get a clear(ish) picture of the "dots" I'll try to get an ID for you, so you know exactly what to do.
Also, give your fish a varied diet, of bloodworms, brineshrimp and daphnia as well as the flake food.
Good luck,
Kathryn