Is sticking a AC110 on a 40 gal planted

[Roadblock]

i would suggest you fabricate your own intake tube end. dont use the one that comes on the ac110, get some small pvc and a couple elbows and design it like a old ship anchor where both ends turn up. then cut some slits into them and create an "overflow" style intake for it. that should be safe for plants and fishes alike.