Are you using muni water? If so, do you allow time for the chlorine to offgas? Although some don't think it goes away -
In water solution, at near neutral or higher pH levels (> 6.0 pH) and with typical sanitizing levels of free chlorine ( < 10 ppm), chlorine will NOT “off-gas” but will remain in solution until
- the chlorine is destroyed in a redox reaction with debris or gook in the water, OR
- it is chemically removed in a deliberate reaction with hydrogen peroxide, sodium thiosulfate, etc, OR
- it is removed via photolysis by sunlight or another UV source.
Chloramines, which may be present alone or together with free chlorine, represent a more complex issue. As a practical matter, most dechlor agents contain sodium thiosulfate which will remove BOTH free chlorine and the most common chloramines.
I’m not sure what you want to know, but you can verify the absence of BOTH chlorine and oxidizing chloramines by testing with OTO (orthotolidine) kits, available anywhere pool chemicals are sold. Just be sure to let the solution stand for 10 minutes after adding OTO, since it can take that long for the OTO to react with some chloramines.
From the interwebs:
- Use a complete fertilizer that is appropriate for your water type
Most packaged fertilizers carry on the label a guaranteed analysis of the elements inside. The most important of these are the N-P-K levels. N-P-K stands for nitrogen, phosphorus and potassium, the three macro elements that plants need to grow.
In addition to these macro elements are a group of lower concentration elements referred to as micro elements. These include calcium and magnesium, and in smaller amounts iron, copper, boron, manganese, molybdenum and zinc.
A complete fertilizer will contain all of these elements in ratios that are appropriate for growing plants. There are formulations made for growing fruits and vegetables that closely match the requirements of marijuana. These are absolutely fine for your garden.
