Owners of large marine aquariums have to do regular water changes, monthly or more often, a messy, wet job that COULD be made much simpler. What I want invented is a "bi-directional in-line electrical water pump" with tubing on either end, that does NOT need to be submerged to work. Here's how I envision it:
Step 1) Plug it in. Stick one end of the tubing in my tank and the other end in an empty 5-gal water container. Turn it on, it pumps the water out into the container. (Like siphoning but faster). Easy on/off button to stop when full. Step 2) Leaving the aquarium end in place, just move the other end to a full 5-gallon container. Flip the bi-direction switch on the pump and it pumps the new water right into the aquarium. No more splashing around like I always have to do now, pouring water into buckets to pump it into the tanks because I can't just pour it in (5-gal containers are too heavy and pouring disturbs the tank far too much) and I can't fit any existing pumps into the small mouths of the standard 5-gal containers that every aquarium store in Los Angeles uses to sell saltwater. This SOUNDS like a simple invention and for years I was sure it already existed somewhere, but I have now been in this hobby for >10 years and have NEVER found a pump that can do this. I've discussed it with many other hobbyists and they all agreed they'd buy this if it existed. The only engineer I discussed it with said it couldn't work because a pump needs to be primed with water so it would need to be submerged to start. I don't know if that's true.
Reward: Make me one...I need it.