I use the whole entire line of flourish ferts 3x a week and have root tabs scattered throughout the bottom. 5ml trace, 2ml comprehensive, 2ml iron, 2.5ml phosphorus, 1.25ml nitrogen, 4ml potassium, 2ml excel (10ml excel on WC day). At start up I did this schedule once a week. As they grow you will start to notice deficiencies, that is when I would start adding more(2x a week). I think my tank is good at 3x week as of now. The plants are growing out of the tank and I have no more algae issue after adding a tad bit more phosphorus. Not to mention the colors look healthy and the tenellus is throwing out plantlets like crazy, and stems need a trim once a week. Keep in mind I do a 50-60% WC weekly. Depending on what plants you have, you will want to add more iron. However, I have my dry ferts on order(N,P,K gh booster), but I will still be using the Flourish liquids for trace and Iron. I'm starting up another 20 gallon, so it was time for the wallet friendly ferts. I also use DIY co2 on this particular setup.