Good to know Tom, I figured less light would help.
The plants definately look better when you get the output right from the bottles but I have a sneaking suspicion that towards the end of the mix life it is pushing some alcohol fumes along with the co2. I beleive if one were diligent enough with changing bottles at no more than one week intervals it would be healthier for the fish, and probably the plants too but it is just too much effort for the results.
I found that by waiting too long to change the bottles it also produced a sort of mulm that settled on the plants. It may have been some form of diatom or algae but it would consistantly be there if I waited an extra day or two between changes and would go away when the bottle was changed. I was running 2 bottles and alternated them so there was always a steady level in the tank, my dropchecker stayed green and the plants are healthy but after one day of no gas in the tank I have noticed the fish seem to have better color.
So I have come to the conclusion that DIY co2 is not a very clean way to introduce the gas to the tank, whether it is alcohol from the fermentation I can't say for sure but I have to conclude that if you want to use co2 do it right and buy a pressurised setup. With a solonoid and timer this also has the benefit of giving your fish a break from the gas each nite.