Sounds like a lot of expense and hassle for a 5 x 5 tent. Is the gain worth it? I don't think I would bother with Co2 with your current setup.
This does bring up a real point.
On my scale. I don't bother, as it doesn't balance. The return is not worth the cost
In tent's or on an average grower personal grow. If done properly, it can be a nice thing to play with.....Plenty of learning in that curve....
It's up to you OP, to figure out if it's worth
your time and expense. It will not make your result any better, as far as quality (potency/flavor) goes. It may increase yield some.
Hints:
Get away from the grow store gas bottles. Go to a gas dealer and get a 50 or 75 lb tank. Much cheaper, and lasts longer...
Be sure you have enough light energy being delivered for the ppm you deliver..... maybe 7500 to 10K lumen's per square foot.....
I don't care what
any guide may tell you. 1500ppm is not going to be worth the cost to make that amount of gas actually work
properly.
At 800 ppm your recovering about half that 30% of plant growth lost to natural botanical factors.
For every increase in gas, you must increase light power to match, and the increase will make less and less return the more you add.
EXAMPLE: adding 400 more ppm to that 800... gets you only about 25% or so, of that first increase. Increase more and the return gets less and less.
You pretty much bottom out at 1300ppm. Trying to run more? You won't add enough light energy to make it worth your time or
money. So anything above 1300 ppm? Is simply wasting gas.
If that space isn't sealed. Your wasting money and time.
ALWAYS stop gassing around 2 weeks from the harvest. Co2 delays proper ripening!