If you're thinking of using it as a way to kill algae, I would not recommend it. I tried it a few times at varying strengths -- weak to very strong -- and many types of algae survived even days of treatment. However, it did seem to work pretty well against snails, hydra, cyclops, and similar critters.
I just plant my plants as they come. Algae is going to get in your tank no matter what. I try to deal with it by messing with fertilizer and increasing plant density. As for snails Ken told me something neat that works well. WHen initially planting drive co2 way up (Like 50-60ppm). THat will disintegrate the snails and then your free of them! Most of my tank i prefer to have the snails.