I feed the fish once a day with misces , I make sure I feed them a bit at a time so none falls to the bottom, I don't have many clean up crew, but it's just been in the last couple weeks it is spreading like wildfire, and it's going on my sand too, I always check my levels, the fish are super happy, but the weird thing lately is all my snails are dying. But that is the only thing that won't stay alive, so I'm scared to buy a cleanup crew, even one day after I bought a sand sifter star fish last week and 2 days later it died, also bought 3 scavenger snails at the same time and they died too, I just bought an RO filter to see if that's the problem, I have only done 2 -25% water change so I guess there is still some tap water left in there, I'm just stumped.