i know there def not the same in quality, my problem with io is it ALWAYS bunches up in to huge clumps, even in the buckets ... i dont get moisture in it. but if its longer than a few months it will clump up, i get the boxes of red sea and it never bunches up..... i know IO is def good but im just speaking from my experience with it, after it bunches up i cant get it all to fully dissolve, the main reason i use red sea is becuase it seems to dissolve so much quicker, i do 25 gallon water changes, i dump the red sea in all at once, within stirring for about 2-3 mins its completely dissolved. I would not want to use it of course if it isnt good for the fish... so far it seems everything really likes it ... i was just wondering if anyone had bad experiences... thanks everyone for the replies!