What is the best way to mix my nutrition! Do I mix them all together once I have tested my water or what? I read somewhere that some nutrition have to go in by their self and don't need to be mixed !
Don't mix the pure nutes together, add them each to water. I usually start with about half the water, add nutes one at a time, then top up with water. Test it after you mix it, to check if you need to adjust the pH or if it's too strong/weak.