I have a stable 2.5 yo JBJ 28 gallon 186 watts metal halide lighting, SG1.025, calcium 440 , alkalinity 9 dKH, nitrates 0, pH 8.3, temp 79 F, water changes - 4 gallons distilled with instant ocean weekly, other additives- iodide, strontium.Tank has many SPS species, zooas, frogspawn, hammer...