puft escape through water

You need to increase the amount of water in the top cell. Creatures can still crawl/fly through tiles if the mass is small enough. Unfortunately I cannot say where the cutoff is, but you could easily find out by looking at the creature’s navigation.

To have a solid Water Airlock make sure Water is on both sides of the seal. What you should do is build two tiles to push out the CO2 and Natural Gas and then destroy them. If you have enough Water it will cover what's needed. Also that Airmesh Tile might not be a good idea, because its pushing the Water back making the seal thinner and could be causing the Puft to escape.

Edited March 19, 2019 by vonVile

Thanks for the tips I swear this game truly is a group effort lol.