[jarthel]

using a dosing calculator, I was able to determine the teaspoons needed on a 1liter water with 20mL dosage. This would last be for more than half-year.

My only concern is, do fertizer solution "spoil"?

Thank you

 

[Hoppy]

Except for chelated metals in the trace mix, the chemicals we use as fertilizers are just inorganic salts. So, ask yourself if salt water "spoils". Of course the answer is that it doesn't, nor does a mix of other salts in water. Some people add a bit of Excel to their trace element mix to prevent one form of spoilage. Others use a bit of muriatic acid or citric acid for the same purpose.

 

[wkndracer]

My trace and NO3 mixes both grew ??? something. After posting and several exchanges including a reply from T. Barr I started adding some excel. Even when I kept the trace in the refrigerator it flaked after about 3 weeks (using distilled water for the mix). Now I've settled on 30ml of excel mixed in the 500ml dosing bottles and I'm able to keep them in the stand without issues.