If you are only using flourish, excel and root tabs you are missing all your macro nutrients N,P and K. Flourish is only the micro nutrients and as the name suggests the macro nutrients are more in demand than the micro ones. You do get some NPK from fish food, fish waste and decomposing plant material but it's not very much. Further more it looks like a 75g tank, could be a 40 breeder too but I'm guessing 75? If so (or even a 40 breeder) you will quickly learn that it gets expensive to use liquid ferts in a big tank, you are mostly paying for RO water with those anyways. You are better off with buying the ferts yourself and mixing up your own liquid ferts (using something like PMDD or PPS-pro dosing methods) or putting the dry ferts directly into the tank (something like EI). Let me know if you understood any of that then we can go from there.