Just registered. I’ve had my AIO nano tank for about 4 months. New to the hobby. Trying to build a reef tank. So far, I have 2-clownfish, a skunk cleaner shrimp, 4-Trochus snails, 4-Blue-legged crabs & 7-very small Nasarrious snails. Right now I have 4 - kinds of Zoathids & one Blasto. Added a live rock which brought in some hitchhikers, but was able to deal with them. Only issue I have now is Cyano which I’m treating w/ChemiClean. Seems to be working. ?Question - I took out my carbon, but left my biological filter media in the tank. Once finished with treatment, should I replace my biological filter media?? I’m assuming yes. I look forward to learning more by reading this forum. Thank you.