Built one of these this morning:
About $4.00 in parts from Home Depot. I put a threaded connector on the end, so I could attach a quick connect valve:
Now I can easily snap and unsnap my hook and swap it out for a gravel vac. I'm quite pleased with the setup. The inside tube is exactly half the height of the tank, so I can walk away and get a perfect 50% water change every time.

About $4.00 in parts from Home Depot. I put a threaded connector on the end, so I could attach a quick connect valve:

Now I can easily snap and unsnap my hook and swap it out for a gravel vac. I'm quite pleased with the setup. The inside tube is exactly half the height of the tank, so I can walk away and get a perfect 50% water change every time.