I am shortly setting up a low light no co2 tank also, I am going to plant what I want straight off, but add fast growing stem plants as extras along with some floating nutrient suckers to use up any extra nutrients while my crypts and swords get going. It will save stirring the whole thing up again later, all I'll need to do is remove the stems. What are you using for substrate? I am using MTS, which has lots of nutrients, thus the need for nutrient suckers. If your only using something plain, it may not be such a problem for you.