Thanks for taking the time to help a beginner!
3 months ago I bought a new home that came w a 10 year old 65 gallon SW FO
tank. My main problem has been a recurrent layer of black stuff that blankets on the bottom of the tank. based on what I have read I assume it is a cyanobacteria. It peels right off and I can clean it out, but it will grow back fairly quickly. I have removed all the larger rocks and scrubbed them clean twice now. My nitrates hover between 10 to 25 ppm
. My phosphates are around 2.5 to 5 ppm
. The pH hovers between 8.0 and 8.3. Ammonia is negative. I recently bought an RODI
filter and have been doing weekly 15 gallon water changes for the past 3 weeks, but the nitrates dont seem to be dropping. I added the whisper AP150 and the SEIO 1000 to help move the water too. I read somewhere that the wet dry filters can often trap nitrates and I'm wondering if that is my problem (or at least one of them!). There is a bunch of tan colored slimey stuff all over the bioballs in the filter and Im not sure if that is good or bad! I feed 1 packet of blood worms a day for the 4 fish. Have I forgotten anything?