Another thing I was thinking of is how calcium, magnesium, sodium, potassium and ammonium, according to NovaCrop Control, can all be antagonistic to each other in the sap if one is high/low vs the other, like on a teeter-totter or see-saw. So one might look at see if one of the four others besides Ammonium is really low, and work to increase that element, and it might (?) help to decrease ammonium?