you need some basic plumbing parts to draw water thru the center drain fitting. Use bronze / brass fittings, not PVC
Get a short piece with male threads on each end to go into the 1" opening, a 90 degree piece, then a bronze shut-off valve. After that connect to your tubing, pumps, whatever, but you need the shut-off valve for safety. Use teflon plumbers tape on all fittings.