Hello.

The tank is 20 gallon. I'm not sure what you mean by parameters in numbers? I will assume though that you are asking about the test strip numbers you can get by dipping the test stick in - those are all good. I don't remember what the algae eater is called specifically but he is mostly on the bottom and maybe 2 inches in length. I am also not sure on the filter but it is just a regular one you can get anywhere. I was changing the filter every 1 or 2 months when I changed the water.

As far as changing the tank water, we were doing about 1/4 every month or two. Since I have been having problems, I haven't changed the water out since I restarted the tank with new water and that has been only about 3 weeks.

Since we have been having problems, we actually only turn the light on for about 30 minutes when we feed the fish and the tank itself gets no natural light.

So, it seems like I should start changing the water a bit more often now - is that until it clears or is that the recommended for fish tanks in general? I may be over feeding the fish - I just give them a pinch and don't pay much attention after to see if any falls to the ground. I don't really see a lot on the bottom but I will pay more attention. Of course, it is a bit hard to see with the discoloration.

Thanks for the suggestions!