I have used Tropic marine pro reef for years, LOVE the salt.
lately I started getting buckets and the salt was turned hard ! so I changed to KZ reefers best salt, Pricey, but I think its worth it, done 3 water changes with it so far, and I get much better results with it. but not that far from TMPR.
I use those for my SPS reef which is ULNS,
all other set ups I have use IO salt, the best salt to price ratio, and it is indeed a good salt !