Your set up looks GREAT!! VERY similar to my planned set up with a Cap PPM-3 and burner.
I hope your lights were raised just for the pic(12-18" works best for me).
If you cannot control the RH W/O exhausting the moist air and wasting your precious tank co2,you should invest in that multi controller to shut down any exhausting during the gassing phase and cycle the two as to save the gas,the temps will rise at that time and the plants will love it at 1500PPM of co2.
Another method of absorbing excess RH is a silica product in a mesh bag (like in med bottles) which can be reactivated in a microwave to dry and reuse,never used it but read about its use.
Love seeing grows so similar to my own.