I just used a small powerhead attached to sponge filter. Only got nitrate test kit, showed below 25ppm. Got dirt? Dirt come form where? Rainwater itself? The water drip from your roof ah? So keng one, polluted until got dirt in rain?

The tank been there for some time only, I only keep one or two guppy in it, was planning to breed my whiptails in it. 1 and a half feet long. So the tank quite mature one.. my CRS also nothing, only the bumblebee started KO damn fast. About one everyday, then one day 2 die at a time. Now I move to a different tank with different substrate (holland sand and jbl sand) they start to stabilize. The white ones became transparent again.