PTFE tape isn't great practice with this type of gas connection, it relies upon the seal/washer. Something else not widely accepted is overtightening this type of gas connection is often what does cause leaks so with a healthy washer just tighten it up until you feel resistance then give it another 1/4 turn
Sound advice, no PTFE tape on the thread of the bottle. The over tightening part is dependent on who’s doing the tightening. We advise customers to use their opposite hand (so if right handed tighten with your left pretty tight) to get an adequate pressure on the washer and create the necessary seal.
From your picture I see you’re using a Pro SE regulator and inline diffuser.
Potential areas that could be leaking:
- Bubble counter. Has four parts; lower section, clear viewing section, upper section with nipple and threaded nut. Ensure this is all screwed together with the black washers on the inside seated properly.
If there isn’t a black washer in the upper section (it’s possible it could have dropped out when topping up the bubble counter with water) it could be leaking from there, but even if it’s not seated properly it could potentially be leaking.
- Co2 tubing. Cut straight and clean. Use a razor blade or sharp knife and run the full length of the blade in a straight action to cut, not force. No scissors. The nut then needs to be down tight to maintain the seal.
- Co2 tubing (again). Same drill as above where the tubing joins the diffuser. Straight and clean cut.
- In-line diffuser. Reliant on three washers to maintain a seal. Two white, one orange:
If taking the diffuser apart for cleaning ensure all the seals are seated correctly when putting the unit back together.
If you’re assured these areas are accounted for you can then look for alternative options.
One other alternative is gassing off, this isn’t to insult your intelligence but I have to ask if you’re running any aeration? I’m careful to not presume anything these days. Have dealt with people that are adamant their unit is faulty until they’re red in the face, only to find out they’ve been running an airstone 24/7 whilst trying to use Co2 injection.
My money is on the PTFE tape preventing a proper seal so hopefully removing it solves this issue and you have this sorted shortly.
As
@Andrew Butler mentioned before, make sure you take into account that once the unit is functioning properly your running time for the Co2 and injection rate will need to be adjusted accordingly.