Is this a check valve?

[zenn]

Is the thing circled in red a check valve? The instrustions "recommend a check valve" so I was under the impression the reactor didn't have one and I'd need to add one. But I dont' know what else this thing woudl be.

 

[tatoofr]

Cant really tell.
Take it off and see if you can blow through it on one end and not the other.

 

[BeanAnimal]

Why not just contact geo if you have questions

 

[AZDesertRat]

Yes, that is an airline check valve. I am not sure if it is CO2 resistant though.