I use KGRO all purpose plant food. 15-30-15. Other than NPK it has Boron 0.02%Copper 0.07%, Iron 0.05%, Manganese 0.0005%, and Zinc 0.06%. When i get low MG signs i throw some epsom salt in there 1/2 teaspoon a galon. This sounds like you MG however KGRO you mix 1 teaspoon per gallon and water...