jer, I don't know the long term effects, first tried it 9 months ago on a 30 gal. A friend of mine been into salt water for over 35 years, raising rare fish for a lot of salt water fish stores,turned me on to it. I was into salt 25 years ago, till my seam split on my 125 gal. I lost my life savings on all the rare fish I lost. I got out. Anyway, I ran into him 9 months ago in Tropiquarium, in Ocean. He talked me into setting up a new tank, with all the new products out there now. I asked him for some culture from his Eheim ( thats the old way to cycle you're tank faster) He brought me over by the Bio-Spira freezer with the owner( both laughing at me cause I didn't know bout the new product out there) They both assured me , I can use this stuff and put fish in the next day. I trust this guy with my life. I set up a 30,added salt, added live rock that evening, Bio the next morning, and 4 fish that evening.I checked the water 4 times a day and watched the fish closely. After 4 months of paranoia, I only started checking 1 time a day. I set up a 55 about 2 weeks ago with Bio again. Softies, SPS's, LPS, fish, all doing great. George K. thank you.