[Delphinus]

I actually would not rule out the false positive still Greg. Some test kits just aren't very robust, although they may say "good for FW or SW" they're not really that good in SW. I never test for ammonia. I do have an ammonia test kit though that will always give a low non-zero value in SW.

Just for kicks, test for ammonia on your old tank. I'm willing to bet you get a positive value on that one. By your nitrite and nitrate values, that tank is has finished its initial cycle. If you had ammonia, you would have nitrite.

In fact, it's almost pointless to test ammonia. It's only in the most serious of tank crashes, or massive death events, that you'd get an ammonia reading anyhow. In 9 years of keeping reefs I've never really had to test for ammonia, and the one time I thought I did, I was completely baffled by the fact that I was showing an ammonia reading when in fact it was a false positive and the problem was something else. I don't even remember what it was, but I remember thinking "why does the ammonia reading always read "X" no matter what I do?"

I'm thinking you may want a different nitrate test kit too. Increments of 20 isn't very high resolution. A reef you want nitrates to be under 10 (not really a hard and fast rule, but typically, a reef has very low nitrates like 2 to 5 ish). The Salifert ones are not bad, the Elos ones are pretty good too. I used to use Seachem and they weren't too bad but I haven't seen them for sale anywhere for a while.