Hi I set up my current aquarium mid October LFS advised to use Prime. No complaints about the product. Just wondering if it lasts longer than 48 hours as all readings for ammonia, nitrite & nitrate are 0 done weekly prior to water change 50% to 70%. I included allot of the the old aquarium media to bring across bacteria and it is planted. There is diatoms present which I thought indicated ammonia was present but no ammonia reading. It is concerning me a bit that I am getting 0 for a n n. PH is 7.4. and doesn't change. Tape water is 0 for ammonia. API fresh water master test kit used.