Yeah, I have used MEI Crystal Sea Marine mix for the past 8 years. no problem. Like they said, its made pretty locally in Baltimore. I buy it in the box and save a couple bucks for the plastic bucket. I mean, after a while, i can only use so many empty buckets. SO PA has been carrying some boxes of their upscale mix. the Bio Assay mix, which is kinda like going from IO to Reef crystals. more Ca. Mg mins and stuff.
I too have gone to hidden reef, aquarium centers in baltimore and Nj. to buy it for less. but PA's price is about the same for the better stuff, Bio Assay, considering the cost of driving and tolls and sales tax. so im getting it here. less driving. last i saw, he was running low. time to restock.