It is best keeping as many leaves green on the plant until week 5 or 6. Then, metabolize the remaining minerals present in the plant during the final 2 or 3 weeks. Total dissolved solids in the final flushing solution is between 400-500ppm. In hydroponics, it is important not to reduce the solution ppm much lower, as this will shock the plants by causing reverse osmotic pressure on the roots. The plant stores excess nutrients in the plant tissue, that are available for photosynthesis. If there is a lack of available nutrients to the roots, the plant will access these reserves and the final product will burn, smell and taste far better.
Botanicare Pure Blend Pro Bloom: 5ml/gal
Dyna Pro-Tekt: 1ml/gal, used as ph up and silicon source
FoxFarm Big Bloom: 15ml/gal
3% hydrogen peroxide: 30ml/gal, every other day