Check the listing for details. 24v DC Variable Speed Pump for Aquarium Hydroponics Submersible Pond Fountain. Condition: New. Listed at 37.62 USD. QuietOne DC pumps range from 132 GPH to 3,168 GPH flow capacity. The small pump is USB powered so it is ideal for emergency use when there is no power so you can run it on a simple USB battery. 24v DC is Energy Efficient Intelligent Marine or Freshwater Pump that can be used External or Submersible Amphibious Perfect for Fish Tank Pond Fountain Hydroponics Water Pump Marine and come with a digital Controller UL STANDARD -- WAVE-MAKING -- CERAMIC SHAFT -- US SELLER Constant Flow Setting: Constant flow has 20 setting levels to control the flow intensity GPH. Select the constant mode from Mode button and adjust the flow 1 – 10 with the Intensity button. 1 = Min Power Consumption Pulse Wave Setting: Pulse Wave flow has 20 setting levels to control the duration of Pulse wave from faster frequency to slower frequency at maximum intensity GPH Select the constant mode from Mode button and adjust the flow 1 – 10 with the Intensity button. 1 = Min Power Consumption Tide Wave Setting: Tide Wave flow has 20 setting levels to control the duration of Tide wave from faster frequency to slower frequency at maximum intensity GPH Select the constant mode from Mode button and adjust the flow 1 – 10 with the Intensity button. 1 = Min Power Consumption Feed Setting: Feed setting allows the user to stop the DC Pump for a duration of 10 minutes, 20 minutes or 30 minutes by pressing the Feed Mode button. Once the selected time is over the pump starts again back to the last selected setting that was chosen.