Bruh, I bought 50lb total for front row ag's two part. I'm set on nutrients for like a decade at my current scale haha
I got over a 1/2 ton of nutes lying around. Thats in dry format not liquid. Emptied them out in 5 gal buckets with seal tite lids. If not moisture will get to em as the nitrates attracts it and will get rock hard.
My mega that I bought a couple years back did this really quick. I bought their first formula and second one.
I'm not a big fan of mega personally. Had ph issues and did not dissolve very well. Ive bought several items over the years from them. And only used a couple of times and didn't use again. Like sweet candy, bud explosion and their call mag formula.
I like to make a concentrated batch in 5 gal containers that have spigots on em. You know, 15 ml per gal of this, 2 ml of that etc. Their formulas would not dissolve in the hot water very well and the product would separate or fall out of solution in about a days time. The cal mag solution I bought I emptied in a 5 gal container and used hot water and I shook that jug maybe 2-300x over the course of a couple months. Never once dissolved and stayed in solution. And it wasn't like I didn't have enough water I had 2x the amount of water I needed to dissolve it.
Raw Cal mag salts worked fine dissolved well. Ive even made my own using nitrate, epsom and su and it worked well.
In my greenhouse I used mega and it worked fine in soil, in my gorilla grows it didn't because animals would dig up the plants to get to the roots. I think it was from the heavy molasses used in the formula.
Ultra sol hydro works well. Use it a 3 part formula. Master blend is another good one. Also have used grow more a lot. I like jacks the best with its high sulfur content.