Especially when dealing with 'is it safe to use' and 'can I economize'---generally take it that if the users on RC trouble to specify brand name and particular product of brand name on something, there's a reason. Buying an alternative cheaper product or 'something like it' is not always a good idea. It MAY be ok, but a novice who hasn't yet had the experience to know the ins and outs of water chemistry, skimmers, and such---is just a lot safer sticking to specific recommendations. At least, if you think you've got a bargain, ask. This also goes for foods, meds, etc. If the lfs is pushing a new product, ask---there, the primary danger is just that it won't work. But be conservative and cautious about what you let into your tank. Anything smelly, pungent, or oily is a real no-no. Anything antimicrobial or antibacterial is a no-no unless you're trying to kill bacteria. 'Kay?