CO2 question

i was wondering if too much co2 can harm a plant. i have one small plant in my closet and i have been using the small water bottle method of co2 and i was thinking about moving to the gallon jug method and i was wondering if it would hurt or help it...the plant seems to be growing rather slow. any suggestions or tips would be greatly appreciated.

Ambient in air is approximately 300-400ppm
Optimal level of 1500ppm
Above 0.2% (2000ppm) CO2 becomes toxic to plants
Above 0.5% (5000ppm) CO2 becomes toxic to humans

Now this is an interesting thought. It really applies to me (it's #3). How much validity is there? I used yeast to make co2 in my grow room.

#1. Plants will use as much CO2 as they are given-- the danger is to the PEOPLE if you use a generator with out a monitor or emergency shut off-- the plants';ll be happy--U B dead!

#2-- the yeast thing does work-- but how much it puts out is iffy... and they only work for a few days before the yeast consume all the sugar then die... you can tell by shaking the jar (or whatever you're using) and if it fizzes-- it's still good... if not- dump it.

#3- you are taking a chance of introducing mold into your grow if it Spurts (often they do) or gets spilled. And yeah-- they smell..

And I had a big problem with mold and was unable to find the source. Cleaned the room. took everything out, spraying with bleach solution, repainting, rehanging lights (after thorough cleaning with bleach also).

You can get the same type of results by doing home-made wine in the growroom (at least 2-3 feet from the plants!) then the plants AND YOU benefit!

I used a half gallon jug and used about a half pkt of yeast every week i think. Changed it about once a week i think. but kept it goin by adding sugar. worked great for six, 2.5 foot tall little bushes. I would just use new stuff before it can get nasty.