If you're using a canister filter that has double isolated disconnect fittings on the inlet and outlet like the Eheim double tap connectors, the ones on the marineland canisters, etc. buy another set. Buy a long hose. On one end of the hose, place your disconnect fitting, on the other end, place whatever adapter you need to connect to your faucet. To drain water, shut off your filter, shut the isolation valves on the outlet disconnect, break apart the outlet disconnect, attach your long hose, open the valves back up, and turn your filter back on and drain to your sink. When you're done, shut the valves, take off the hose, connect your filter, open the valves and turn it back on, and stick the hose in the tank. Connect the sink-end of your long hose to the faucet to fill back up. Of course, this is only for bulk water removal and filling. For gravel vacs, I would continue to use a plain siphon and bucket. Just get good at it to minimize the amount of water you have to dump with buckets.