the 50 lb bag was the only one ive used and tried. I won't recommend the other ones just because they haven't been tried as after market additives whereas the dow has been.
Although i'm sure the other brands will work just as well you will have to make that call at your own risk without any input or suggestion from me because I don't feel the risk outweighs the price of your livestock in your tank.
i know that doesn't help so..... sorry
