ok so you know i have a new tank, its been running for about 2 months now. the water was crystal clear the first 2 or three weeks, since then its been cloudy, on the 14th i did a water change and a vaccuming. the next morning i see this: last night i did a 25 percent water change again added accuclear and stresss coat. im afraid my fish are gonna die. tested the water, ph is 7.0 high range ph is between 7.4 to 7.8 ammonia is 0.25 before water change and 0 after. nitrite is between 0 and 0.25. and nitrate is 5.0 before water change 0 after. is there any chemicali should be adding? are 25 percent water changes enough or do i have to do a larger change.