Rat watering system help

[MootWorm]

Hey guys, I was hoping to get some help with my gravity fed watering system. After dealing with faulty T-connectors, flooded tubs and many trips to the hardware store, I finally have all the issues with the line worked out. However, I am having some trouble with a small leak at the joint of the water container and the barb that connects to the hose. I've used tons of teflon tape but I haven't been able to get a good seal. Next I was going to try getting a new connector, adding a nut onto the back of the connector(inside the chamber), or starting fresh with a new container altogether. Or a combination of all 3 lol. Any suggestions? I'm using 5/16 flexible tubing btw.

[The Serpent Merchant]

Have you tried without any Teflon tape? I've found that some types of threads actually do better without any.

[EAC Reptiles]

Check the sealing ring on the inside of the valve. See if there are any tear or deformations in the rubber. If all looks good you can use some petroleum jelly on the seal, help lubricate the seal and cause it to work the correct way