My first Aerogarden Mini came with a really loud aerator.
Aerogrow customer support was wonderful, as always. They couldn't send a replacement part to fix this loud mini, so they sent me a whole new mini. Which was much quieter.
But I still didn't like the fact that by design, the mini3 cycles power on the aerator - 20 seconds on, 40 seconds off. The new mini was definitely less unpleasant, but I prefer white noise constant, not cycling. (Note: a mini/3 is not the same as an Aerogarden3. They quit the dratted 20/40 second cycling in the later models.)
I placed the loud mini in the garage, unplugged. Guilt-ridden at using a device which had already been replaced, I left it there. But it kept calling to me. I wanted another Aerogarden. And there it was... So I bought another seed kit, and plugged it in again. And the light from two minis no doubt made both grow better, as they were now re-united in my office.
Except, of course, they were too damned loud. And the point-counterpoint of two cycling motors, is not an improvement over one cycling motor...
So - the mini has a simple air tube from the base, into the bowl, and from there into an air stone. (I'm really grateful twoshoes put up his aquarium pix, leading me to think this through in aquarium terms. Not that my further actions were his fault, or Aerogrow's...)
So - I bought an external air pump (Tetra Whisper, max 10 gallon aquarium) and a little 2-output air flow control valve widget, and some standard air tubing. I saw the pumps and valves online for $less, but then you have to pay shipping and wait, so in net, $16 to the local pet shop, where we could pet the bunnies, was a better deal.
I removed the internal aerator from the base of the loud mini (screwdriver & scissors for wirecutters), and hooked it up to the external aerator instead, via the 2-output air valve. Then I also hooked up the second, quieter, mini3 to the air valve. Within a few days, I decided I was sure, and I was tired of listening to the cycling, so modified my newer "better" mini, as well as the salvaged original one.
The noise level migrated from the internal aerator motor, to the air stones / bubbles popping. I spent a fair while trying to tune this with the air valve, but they're still loud. It's just a lot more pleasant as a constant white noise, than with that infernal cycling.
I'm fairly confident this mod violates the warranty.
The minis right after I hooked them to external air, and 4 days later. It's not obvious, but the twinkle phlox wasn't blooming at all then, and now has 3 clumps in bloom. The petunia has 2 flowers and is working on a bud.
Surgery on the mini : before and after removing the internal pump (white square is the silicone-ish gasket around the internal aerator):
The valveplex (actually added another check valve after this picture as per Joyce's instructions - she's got the aquarium experience). Anyway, you get the idea. The blue dome thing is the air pump. Hose goes out (now into checkvalve and then) and into 2-output control valve. From there a hose goes to the air input valve on each mini bowl.
And a peek inside the mini with small roots - air stone bubbling.
Oh! And Blister posted me a picture of an awesome T-shirt for my modding efforts: