We just can't seem to get it right - try as we may - first the disease - so in goes anti biotics - (I think it killed all the friendly bacteria) , then all the sick Danios died anyway, next went the Otos but the platys made it through (and the Cory). But we had serious ph and NO3 NH4 levels - finally got ph under control, still hoping the cycle will return and pull down others - so far no luck. The male platy died today, the bid female seems to have lost color and has this dark pattern all over her back - is this a new fungus or bad bacteria - anyone know? Thanks for any suggestions.