Eh, I wouldn't get my hopes up if I were you. Most of the products like that are just snake oil. The only way to manage very few water changes is with a large quantity of live plants, beneficial bacteria, and just the right balance. You just can't get that out of a bottle. Besides, this thing is telling you it's going to seed your tank with a ton of algae. Who wants that?
I dunno, personally I have 6 tanks--I don't find that weekly partial water changes are all that difficult. It takes like 5 minutes per tank--really not that bad considering that in exchange for a few minutes of work you have a beautiful fish tank to stare at and happy fish to stare back at you.