Well, not sure exactly but the pH is a little higher then I run at. I tend to run lettuce at 5.5 to 6.0 and I never run the nutes more then 1/4 strength of what they say on the bottle.
Also miracle grow is ment to "enhance" the soil. You may need to add micro
nutrients that the plants are not getting in the hydro unit. Fertilizers like miracle grow are not intended for hydro systems. Better to stick with a hydroponic
nutrient that has all the components the plants need.
Maybe you will get some more answers soon...