Over the past five years I've switched from Kent, to IO, then Reef Crystals, then Tropic Marin Pro, and now use Salinity. Never had any issues as I used the 'new' stuff for 20% or so water changes. The tank only had LPS and softies but did have some seahorses (there supposed to be sensitive I guess). As far as mixing I liked the TM Pro. It was clean and had no chemical smell, very small powder like crystals. It was always a little low in Ca, and Alk as compared to the label. So far the Salinity is fine, mixes very close to what the lab sticker says and is high in Ca (440), Mg (1350), and alk is around 9. It does have a chemical smell though but so did the reef crystals if I remember correctly. I like the Salinity because I don't have to do much dosing and when I travel the higher levels hold the tank over until I get back because the wife doesn't want to mess with the tank and chemicals. Oh, the Salinity bucket is awesome! It's got this spin top locking mechanism that you just press with a finger. My wife could never get the IO buckets open. There's nothing wrong with IO and I think I switched just because at the time I was new to saltwater and was more or less experimenting to see what got the best results. My LFS has a bucket of the Brightwell salt and I might try that next but I heard the buckets are a pain to open so that may be an issue. The extra CA, MG, and Alk along with the easy open bucket make Salinity a keeper for me and my LFS keeps it in stock.