I have followed many diffrent instructions for the diy co2 and I cant figure out, I would like to start it tonight but only one of my bottles are air tight. Would one be sufficent? Regualr sized water bottles. 10 gallon tank.
Same, I run a 2L soda bottle for my 10gal. A regular soda bottle is airtight when the cap is screwed on tight, and if you drill the hole in the cap slightly smaller than the OD of the airline going in, you don't even need to seal that really.
I punctured the top of a two litre bottle with a knife, fortunately i was well versed in this procedure from my younger days Then put the airline tubing through the hole and put silicone on both the inside and outside of the top around the tubing. Waited a few hours, mixed up my yeast, screwed on the top and off I went.
Just inside the cap. My tubing doesn't extend but about half way down the cap. NOT IN THE LIQUID... There only needs to be about an inch or so inside the cap.
You will kill your fish if it is in the liquid. What I did is I took a drill bot that is one size smaller than my airline tube, and I drilled a hole in the top of the cap. I then cut the airline tube at a very shallow angle so I could stick it in and with a pair of pliers, pull on it and pull it into the hole. This way keeps the CO2 from leaking without the use of extra silicone.
Same here David, I was having issues sealing these dumb bottles, tried everything, in the end I went back and used that method, its worked like a charm too. My plants thank me, lol.