One of the funnest things to do with a heavily populated zoa/paly tank is to cut all flow, and add a cupfull of live baby brine shrimp to watch all the polyps catching meals. And the hilarity that ensues if you have and cardinal fish in the tank as well.
Dre tested my water too and some of my levels were way off compared to my api kit. Well only my Calcium was off but everything else was pretty close or on spot. I don't trust my api anymore except for testing my nitrates, nitires, and ammonia. Everything else seems to be giving me a wrong reading. API expire much faster and end up giving you a bad reading. They are cheap for a reason
I am going to be switching over to salifert test kits. Seem a lot more reliable and accurate than api.