Yeah, but the problem is finding the exact bio ball that fits over the impeller blades - I tried doing this with a bio ball that wasn't quite right and it worked for a while but then got ridiculously noisy and finally the pump just decided it wasn't going to turn that extra load anymore. Basically, that's why I even had a wrecked impeller to try modding - I'd had to trim 3 of the blades off to fit that bio ball on there in the first place, and it was useless after with only 3 blades on there.