you have probably over stocked the tank early and it has not cycled yet do to the over stocking, and the fiilters and cycle can't catch up . you ned nitrate in the tank for sure . use a filter from a friends establised tank and just open the lip and wash out the filter in your tank , it will trick the tank into thinking it has cycled and then do a 10 to 15 percent water change every 4 days till it clears . it should all work out fine