[russell911]

just got back into the hobby after a 15yr hiatus.  I purchased a 3 gallon PET fermonster, but didn't realize how thin the walls are and how difficult it would be to move it without pushing air out of the airlock and then creating a vacuum that sucks in airlock water after moving.  Does anyone out there have any tips for this?

[BrewBama]

Can it fit in a milk crate or some other crate with handles so you can lift it?

[Drewch]

I have a couple of the same fermenters, and rigid secondary containment (like the milk crate suggested above) is the only way to I move them that I've found that doesn't cause some flexion in the sidewalls.

[neuse]

I've seen pictures of a carboy harness: https://www.northernbrewer.com/products/northern-brewer-universal-harness
I haven't tried this, but it might work well.

[Bob357]

Pick it up by the ridge just below the lid. I did that routinely with my 7-gallon Fermonsters so should be easy with the small one.

[Drewch]

Pick it up by the ridge just below the lid. I did that routinely with my 7-gallon Fermonsters so should be easy with the small one.

I find that even that causes enough flex in the sides of the 3-gallon ones to trigger the air exchange the OP is looking to avoid.

[Richard]

I've seen pictures of a carboy harness: https://www.northernbrewer.com/products/northern-brewer-universal-harness
I haven't tried this, but it might work well.

I use a similar harness for a 7 gallon Fermonster. I haven't noticed any buckling of the sides. You just need to remember to put the harness on first, before you start filling.

[Cameron_l]

I purchased a solid lid (no holes) to  move it before fermenting. Then I use a Cold Crash Guardian (1 gal. inflatable sack) on the airlock. This gives a large cushion of CO2 to prevent suck-back when cold crashing, but also helps with the flexing of the Fermonster when moving it.

[saaz amore]

If you're using an S-shaped airlock, try fitting a cheap latex balloon over the top. Give the fermenter a little squeeze and see what happens.

Filling the balloon with a little CO2 first might work as well.