I agree with Jim. I bought Salifert ph, kh, nitrate, nitrite, ammonia, and phosphate. This week just for grins (and comparison) I bought AP ph, kh, ammonia, and phosphate. The AP were about 1/2 the price, easier to use, and IMO had more viable scales.
50g, eco complete, am1000, pressurized co2, just went back to 3wpg