I only give myself an A because I believe that there are many ways to run a system but sometimes you can overcome many problems by being observant and controlling as much as possible in your system without resorting to methods that may be more harmful to your system I have good coral growth and little to no algae I have some small life for a cuc that helps I change 2 gallons per week and add pe mysis shrimp daily and have had no problems except for some aptasia that showed up but currently I eradicated the few I had seen with a little help from a peppermint shrimp that I recently received unless I need to test for possible problems I use my eyes to monitor what is happening in my system and respond the best way possible if needed.