I mix in a 5 gallon bucket and always use 3 cups of reef crystals to get 1.026.
That is alot more salt to mix a 5 gallon bucket. I use h20cean about 2 1/8 cup for a little more than a 5 gallon bucket. i use the h20cean bucket to mix my salt, its a little taller than ur average 5 gallon bucket, and its mixed at 1.025. I was considering switching to reef crystal because the lfs that i purchase my salt from is discontinuing h20cean, im glad i read this thread.
well we are talking about reef crystals here, and the recommended mix is 1/2 cup per gallon and I do get 1.021 if I put 2.5 cups to mix 5 gallons. I just need to adjust it to 3 cups to get 1.026.
so the plausible explanation is either SG reading is incorrect, or the LFS scooped out some salt for the yield to be 100 gallons instead of 133 gallons at 1.026.
FWIW, I never measured the actual yield of a bucket of RC, but on 3 buckets, I have weighed the new bucket and sure the weight was exactly as labeled. On a bucket of Seachem I bought from LFS, the weight was less than the label so I am assuming that is why the LFS hastily picked that particular bucket for me when I bought one.