DT Gas Exchange with Sump

[48hughey]

I just moved everything from an all-in-one setup to a tank I drilled and plumbed for a sump (29g DT, 10g sump). Since doing this, my screen top is no longer sufficient due to the uncovered corner (where the equipment was sticking out).

Also since adding the sump, my evaporation has skyrocketed, and due to space limitations, the sump is small and the return chamber needs to be filled twice a day (ATO is the next item on my to do/wish list). In order to slow the evaporation and remedy the problem of the hole in the screen top, I put on the glass top that came with the tank.

Is surface agitation/gas exchange in the display necessary with the sump? There are many points where oxygenation occurs in the system (surface skimmer, drain to sump, skimmer, waterfall from refugium section to bubble trap, and I put a small pump in the return section to keep the surface agitated in that section as well). The evaporation has slowed down a lot and heat has not been an issue, but I want to make sure my fish will not suffer from a lack of gas exchange.

 

[Big G]

When you think about it, lots of folks use canister filters under their tanks without lots of problems on their closed systems. They rely on the surface agitation only for gas exchange.
On your DT, does your return line agitate the surface?

 

[48hughey]

On your DT, does your return line agitate the surface?

It does, but with the glass top, I can’t imagine it creates much beneficial gas exchange. That’s why I am wondering if the oxygenation can solely occur in the sump without causing problems?