You could use shutoff valves on either side to isolate and remove if you wanted to. I just shut my filter off and have a bucket close by, remove hose from back of tank and tilt it toward the bucket to dump most of the water out of it, and then remove the diffuser. I just keep the hose propped up so it doesn't drain out. It's actually very simple to remove and replace. Does your Eheim model come with a set of disconnects? I would go with an Eheim 2217 for that tank.