i mostly test ph and nitrate. I used to test ever week, but i haven't tested in months, once you get your tank going and it's been running for a long time you can normaly tell if there is something wrong :wink:.
HTH
I've seen this tank before and it's great. It's amazing how you seem to be able to keep the reef going without a heater. :?
Ive also got a nano/mini-reef going in the same way without any supplements, kalk, skimmer, basically just the water and LR and LS. But it's nothing to compared to this...