We checked all the paramiters in our tank and they are perfect! I really think the mico algae is helping with keeping the nitrates down! We are going to change the crushed coral to sand after we take care of the flatworms. We bought some flatworm exit to get rid of them. We are going to try and put a sock on the end of the tube to catch all the flatworms and pump the water back in and continue to suck as many out as we can after they all die. I know this is going to be difficutt, but we have to get rid of these flatworms, we are getting more and more. Does anyone know if the flatworm exit will kill our brittle starfish??