I too go through a large amount of minnows (fatheads up here). I usually get 1 lb each Friday for Saturday fishing for my buddy and I. I have to get them beforehand as we are on the lake at or before sunrise and the bait place isn't open for several more hours.I'm buying and holding 3-4 pounds of #4 shiners at a time. The big thing with these really Diffusers than stones is they have Low Pressure and High Pressure stones. It takes both outputs from the 12 volt pump pictured to product fine air bubbles across the whole disc face.
On a slightly different note, the dentist office that I take care of their boats replaced the air compressor in their office. I got the old one. Well it produces 5cfm at rated pressure oil-less air. This compressor would do an entire bait shop air supply needs effortlessly. I am thinking of setting up a tank for Shrimp & croakers too, maybe even freshwater shrimp. Here, everything eats a shrimp.
I store max 1lb in a 5 gal bucket and normally use an aquarium pump plugging into the outlet. A few weekends ago I was going to take a coworker on Sunday in addition to my usual buddy on Saturday so I picked up 2 lb of fatheads. That quantity would not last more than a few hours in one 5 gal bucket so I split them into two 5 gal buckets. Only one pump so how am I going to keep both aerated?
Never thought of it before but I have a 60gal air compressor in the garage for side projects and running tools. I just put the hose with the air attachment nozzle in the bucket. Turn down the nozzle to a low enough air flow and voilą, bubbles out the wazoo. I could keep 100 5 gal buckets going with the big compressor.
Hardly lost any minnows in the post month even in the 90 degree+ heat.
Just make sure your compressor is fully pressurized when setting the air flow or there will be issues when it autostarts to fill back up. Issues like blowing half the water and minnows all over your garage floor due to the air pressure in the line. Compressor is big enough that it hardly autostarts all day to refill with the low volume of air constantly blowing into your bucket.
Pocket Blow Gun with Industrial Coupler
Here's my compressor. It was about 1/2 the price in the fall of 2019 when I replaced my old one. It is 11.5 CFM at 90 PSI. Mine is kept about 140psi.
https://www.menards.com/main/tools/a...07-c-12910.htm
I also change the bucket to new water everyday. The old water is good stuff for the tomatoes and peppers I grow. Much better than the city chlorine water. When I pick up the minnows, the baitshop is right next to a reservoir. I also fill up five or six 5 gal buckets of lake water for the minnows so I can keep them alive for the week if I have any left over. I hardly ever do in July and August because those are the best crappie fishing months of the year.