no, that one sounds like a bro science hack to make calmag and I would avoid it at all costs. The vinegar takes about 21 days to ferment the goodness out of the burned egg shells, but there would be virtually no benefit in applying egg shells to your soil without fermentation, because it would take around 3-4 months to break down into the available calcium. Any grocery store has the apple cider vinegar, so take the extra care to do it right. In the meantime, your plants are going to survive till Friday. Just as a slight scolding, you should always have calmag on hand before starting a grow, just in case.
I get my thanks by seeing great grows and knowing I helped. Nothing else is necessary. For pH down I used a 1:15 dilution of battery acid, made by replacing 1 cup of distilled water in a gallon jug with 1 cup of acid from the local car parts store. This makes it pretty harmless to us, and it works just about the same as the GH ph down for a fraction of the cost. For pH up, I store a very weak solution of plumbers lye in a glass jar of distilled water. When you are adjusting the pH, get everything mixed in that you are going to apply to the plants, and pH to 6.2-6.3 immediately before applying it to the soil.I hate to keep asking you questions, but I know you're extremely knowledgeable in this area. Is there anything you suggest to "pH low"? Would a General Hydroponics pH Down work? Just mix in when feeding or with water alone?
Side note - if this forum were to ever start an "expert grower" advisory board I would 100% donate to it, I truly appreciate you taking time to share your knowledge with us here and wish there were a way to thank you.
