I use a modified method of EI dosing using Potassium Sulfate (K2SO4), Mono Potassium
phosphate (KH2PO4). I quit dosing Potassium
nitrate (KNO3) as my tank is overstocked and the plants get plenty of nitrates without having to dose them. I dose my macros 3 times a week and traces 3 times a week, on the 7th day I do a 50%
water change. I order all my dry ferts from Orlando at greenleafaquariums.com. They aren't the cheapest but the product is very good quality, they usually weigh more than ordered, and the shipping is super fast.