Review on KEDSUM Battery Aquarium Air Pump: Rechargeable and Portable Aerator for Fish Tank and Outdoor Fishing, with One/Dual Outlets, Ideal for Fish Transportation and Power Outages by Jennifer Davis

I got these to replace my old Mr. Bladder pump that I've been using with live minnows and shrimp for years. Every few years I have to replace the bubbler box because the membrane cracks, or the drive arm corrodes and breaks, or I accidentally left batteries in over the winter and they ruined the battery posts. This little guy is the ticket! It's rechargeable, so there are no more expensive D-type batteries. It lasts around 18-20 hours on a charge. If you're on a boat with a USB charging port, it can last as long as your big batteries last, which is practically forever. It's a low whisper compared to the old bubble boxes we've all used. If you use it all day, plug it in to charge and use it all day tomorrow and the next day and the next. If you do this with a Type-D battery, you'll set yourself back $30 for the batteries alone. It's SO worth the money.