Just getting back into the lifestyle after a 10-year hiatus. Wow, have things changed. Got a lot to learn and relearn, so I'll have a lot of questions (for example, we don't kill livestock anymore to cycle our tanks!). that's a good change for sure! I'm in the process of cycling a 400-gallon mixed reef, with about 125 in the sump. Been using the Dr. Tims method to cycle and can't seem to get the ammonia below .03ppm. Nitrites hovering between 0 and 3ppb, and nitrates between 9 and 10ppm. Back in the day, ammonia had to be 0, no exceptions. I'm using the Hanna marine master. I may switch to the old-fashioned match the color system. Been trying to get it right for a bit over a month now.