Dear Dan, Virtually every nutrient product I have seen has instructions on the label noting to store them in a dark place. They aren’t kept in the dark at grow stores, so what’s up with that? Does this lead to degradation of the products, and does it lessen the effectiveness if stored in a non-dark area? – Salsa Verde
The hope is that the grow store doesn’t have the product in stock for long enough to do any real damage to the nutes. The real problem arises when growers store their nutrients in their growroom exposed to HID (High Intensity Discharge) lighting. Many times I’ve been in space where the fertilizer bottles were on a shelf in the grow space and they will degrade quickly in that scenario.
Some grow shops will show display bottles and then go get your bottles from the dark back room but they are few and far between. Your best bet is to ensure that you’ve purchased a fresh product that hasn’t sat for months on a store shelf under fluorescent lighting or, god forbid, sunlight by asking the clerk if there are any sealed boxes of the nutrients you desire. Once you get the bottles home, store in a cool dark place for the best longevity.