My grow out tanks are 20G. Not sure which ones you're referring to.
Here's what I'm working with...
This closet can be emptied and the doors removed, shelves installed.
This desk is 2" too wide to fit in the closet, unless I can maneuver it in when the closet is empty or cut off 1" on each end.
This cedar chest must stay in the room too.
One plan would to be to put the entire desk in the closet and keep the chest in the same spot. This would allow access to the desk but get it out of the way.
The second plan would be to put the chest in the closet first (It is only used twice a year for seasonal clothes) and put the desk in front of that. This option would free up the most area, I think...
Either option would free up the left side of the room from the closet to the far wall with the window, next to the BRT station.
I'm also planning on altering my hatching station:
If I lower this level by 1' I can add two levels above it. Probably make a wooden stand for this instead of the milk crates.