Help with plumbing for a bulkhead

I want to install bulkheads onto an exo terra 24" x 18" x 18" vivarium to run a filter to filer a flooded bottom. My problem is I am unsure of what diameter tubing is used on either the cascade filter or the zoomed filter. The manufacturers could not tell me, supposedly because they are not made to run to a bulkhead. Does anybody know what size bulkhead or hose barbs to use for standard canister filters? I wanted to possibly use a bulkhead that would accept 3/4 inch fittings, ie strainer for intake, threaded fitting and nozzle for return and 3/4 inch threaded hose barbs? Will 3/4" hose barbs work or do I need 1/2 inch? Any help would be greatly appreciated.