Gas for Hyperbaric treatment ?

[rjack321]

I would use 100% and take air breaks every ~15 mins.

 

[VsubT]

Fiberglass tanks designed for horizontal use may not have the hoop strength to withstand being filled with water while on end. Vertical tanks are available, might take some doing to find one in that size.

The bigger concern is actually not crushing during backfilling. That's pretty manageable though, by using different fill types and/or filling the vessel partially as you go.

Lance