I've set up a 12-gallon nano tank. I put in about 15 pounds of live sand (purchased in a bag from Petsmart), 15 pounds of base rock (CaribSea fossilized/petrified reef rock) and the water two weeks ago.
About a week in, I poured in a bottle of Bio Spira, just for the hell of it, and because I didn't really know what I was doing. I've been measuring the water, also just for the hell of it, getting 0 ammonia/nitrite/nitrate -- exactly what I expected because I don't have an ammonia source yet.
I decided to put in one raw shrimp to start the cycle. I did this 24 hours ago. I just measured the water and got a reading that surprised me: no ammonia (that's not the surprise, because I know I was impatient on the test), but 3 ppm
nitrite and 40 ppm
I don't know how I'm possibly getting nitrite and nitrate readings at this point -- I was just looking for the first signs of ammonia. Is it possible my live sand and the Bio Spira already started cycling my tank before I added the shrimp?
This is my first marine tank, but I've been educating myself and these results surprise me given what I've read.