Do you use the water from your breeding systems for the garden? I've seen that work great for ppl. Even a growing method designed around it that raises talapia at the same time.
You could line them with felt and that would protect them and take up a lil space if you thing you need to.
Also, you might be able to find aluminum tubeing to use as a "decorative" cove for the bolts. Like a sleeve maybe...
Dry hit is when the liquid doesn't wick fast enough to keep up. VG is thicker, and can cause dry hits for some with the high VG content liquids. Doesn't meen you will have them though.