Following along with this one , i set up a 300 DD with a 220 basement sump , bare bottom , marine board and dry rock , my situation is i started with Siporax media , i ended up taking most of it out as i cant get reading to even register for No3 or Po4 ?? i have 4 larger fish and about 10 smaller fish , i feed a sheet of Nori a day and at least the equivalent to approx. 6 cubes of frozen every other day and still no readings , i ended up taking most of the siporax out , but i had a Alk swing a month or so back and lost a bunch of SPS i think my corals were pretty stressed already from the low nutrients .... i have some as i have GHA , and some cyano , the SPS i do have left are doing good with coming back . I run a fuge and a skimmer but i run it on the dry side as i only drain whats in the cup once a week or so to keep oxegeyn going and as much nutrients as possible in the water , i don't want to start dosing No3 or Po4 as that can get really out of wack quick !