I am confused about the PH of my fertilizer. I mixed just 1/8 of a teaspoon into 1 gallon of distilled water. I used my Ph meter and my Tds meter to measure this. The results are 4.5 PH and 73 TDS. That is way low for PH. Is it just the brand of fertilizer or what did I do wrong with it. The NPK is 7-8-6. This is Dyna-Gro.