I have seen people recommend the use of root tabs for certain substrate rooted plants, and I'm just wondering if there's a certain brand/type that is better than others? And are they recommended for all substrate rooted plants, or are some just heavier feeders than others? I have an amazon sword, some corkscrew val, and another unidentified plant... i will post pictures of it soon though. Would they all benefit from root tabs? I already dose with Seachem Flourish Comprehensive twice a week, but it just seems like the amazon sword especially isn't doing as well as I would like. And are root tabs purchased in the fish section/at the LFS or garden centre or some third place? I was at PetLand today and looked, but couldn't find anything.... all they seemed to have was liquid fertilizers.