In my 12 gallon, I currently have a pistol shrimp, a watchman goby, 2 hermits, and 4 snails. I cycled the tank for 5 weeks before putting fish in, I do at least one weekly water change of one gallon. My ammonia is at 0, Nitrites 0, pH 7.8-8, and nitrates are 80-140. The nitrates are worrying me because I cannot bring them down, does anyone have any suggestions? I feed half a frozen cube of mysis every other day. Secondly, I usually see my pistol shrimp out and about once in a while, especially when feeding, but haven't seen him since Saturday, this is really worrying me and I wonder what is happening or what I should do, should I add iodine? this has happened before when he's molted (i knew because i found the sheded skeleton) but it's only lasted about 36 hours before i saw him again and that was only 2-3 weeks ago.