hey I just got done with a 25% w/c and decided to test the water, I have the API 5 in 1 strips so I don't know how accurate it is but my nitrite reading was 3ppm! The fish seem to be fine but who knows, I just bought 2 rainbows today and put them in the tank. so my current stocking level is 3 rainbows 5 neon tetras and 1 serpae tetra. It is a 75 gallon tank so its very lightly stocked right now. I did what rex grigg said on his sight which was to add quite a bit of plant mass and then add fish, this tank is only about 3 weeks old and I don't want to lose any fish please help. there is a pic of the tank from about a week ago in my journal.