Canister filter bulkheads and head height

[the_deeb]

I'm working on a new paludarium setup (build thread here: https://www.monsterfishkeepers.com/forums/threads/walnut-paludarium.681486/page-2#post-7681687).

Planning to filter it and run a small waterfall with a canister filter and plumb the intakes and outputs through 1/2" bulkheads. I was thinking of drilling the hole for the canister intake slightly above the water line to reduce the risk of a leaking bulkhead and then runnin a down pipe into the water. I figure this is how most over the rim canisters work so it shouldn't pose any problems. Any thoughts on pros and cons or issues vs. having a fully submerged bulkhead?

The second question involves head height for the canisters. I'm planning to T off the return is have have part of it return at the water level and the rest feed a waterfall (gate valves will be included to regulate flow along both paths). The waterfall output is around 60" off the ground, but only around 15" above the height of the water surface. What head height would the canister have to be rated for to ensure that it can pump up to that height?

 

[tomojsg]

i have my canisters hard plumbed into the tanks on the rear lower center
of the tanks this way there is always water in the canister and i do not have
to worry about the pump running dry. this position also allows more debris
and gunk on the bottom to get sucked into the canister but high enough for
sand and other substrate not to get sucked in and ruin the impeller. there
shouldnt be any leaks unless there's something physically wrong with a
part like the bulkhead or a a seal on the canister but those things are easily
prevented by silicone-ing the bulkheads and using clamps on the hoses
and making sure the seal is in good condition without any damage when
cleaning the filter out. as for the head height most stronger high end models
like fx5/6 or eheims should have no problem pumping at 60" head height
but you can always put the canister on a milk crate or something to decrease
the distance/head height from the canister to the tank to decrease the amount
of flow lost at higher heights.