Amazon has lots. EcoPlus 75 GPH (284 LPH, 5.75W) Submersible Water Pump w/ 6 ft Power Cord | Aquarium, Fish Tank, Fountain, Pond, Hydroponics.I have two of these. One moves water from a RO/DI holding tank to different output tanks. Second pump pushes water to flower beds. It is variable speed.
Have you thought about creating an airlift?
Amazon has lots. EcoPlus 75 GPH (284 LPH, 5.75W) Submersible Water Pump w/ 6 ft Power Cord | Aquarium, Fish Tank, Fountain, Pond, Hydroponics.I have two of these. One moves water from a RO/DI holding tank to different output tanks. Second pump pushes water to flower beds. It is variable speed.