You can grow your plants without flourite or liquid fertilizers. I grew some plants without either. The liquid fertilizer was the first thing I tried. It worked well, until the algae made an appearance. It covered nearly everything in my tank, and it was the tough red algae. Talk about a headache. My new tank has flourite in the substrate. It is certainly more conducive to a planted tank than plain gravel. I really like the flourite, and it lasts nearly forever. Your plant growth will be severely limited if you don't use something for the plants. Just be careful when using liquid fertilizers!