i using marc weiss bacteria.my rocks about 2 years from old tank so should be ok right?thanks for all your help so about how long to cycle then ok?me got refrigerium,deltec NF511,phosban FR,whats a good CR to get dual or single chamber wats the diff?using most of the salifert test kits,i am new to salifert anyone knows for KH/alkilinaty slight colour change can already?thanks cheers.thanks for al yor help.hey bros cheato the underneath will die if no light?or must harvest often?thanks