Some additional info ferts are all mixed with 250 ml water. So I'm adding iron is 0.15 ppm, plantex is 3 tsp into 250 ml water, nitrate 3.78ppm, phosphate is 1.06 ppm. Drop checker is a yellowish color. Co2 is run into mini powerhead and sprayed through a spray bar. There are 3 fish, 2 dwarf flag chiclids and a oto. The oto was just added today. Substarte is all purpose sand from low's with api fert tabs. VaughnH thanks for the diy drop checker artical and reference solution as my lfs would not order me one and had 50% of the parts already on hand. If any more info is needed just let me know. Thanks again for any help.