I tested my tap water again today, and found there were no phosphates, which is excellent! This leads me to believe the algae bloom I have had trouble with in the tank, was due to the build up of organic material in the fluorite bed. I am very happy to have removed that organic sink, replaced with a sand bed. With regular water changes and the addition of SeaChem PhosGuard, I think we can have pretty high quality water for the fish in the future. By the end of the week, the tank water’s phosphate level should have dropped to near undetectable levels.