Can you take the air pump apart? There is a diaphragm inside that sometimes cracks. It can be replaced,or at least in the olden days aquarium stores carried replacements. Sometimes one can get a few more months out of the current one by using petroleum jelly on it. I think that is what aquarists used to do years ago.

The powerhead may very well do a better job aerating than the air pump. It will certainly do a better job of mixing up any particulate matter in the system.
Renais

A circulation pump could never do what an air pump can,otherwise why must the aquarium include one eventhough it already has a circulator. How can one put it to the test? Try each and take note of the foam head.

It is my understanding that the purpose of a bubbles in an aquarium is to move the surface of the water so as to keep it mixed with the water lower in the tank. It is the surface area of a tank that determines how many fish can be stocked. A tank shaped like a martini glass would be superior for this than a tank shaped like a triangle with the point up. The bubbles themselves add an amount of oxygen exchange that is minimal. They are mostly decorative and the bubbles serve to move the water.

What one needs to consider when using a powerhead is how it will affect the bacteria we are trying to grow. It might be a bit like a Vita-mix on them. Maybe there is a slow speed on them?

Agree with EQ2. Too much bubbling action can, and will, rip the biology that you're cultivating into shreds.

Also, tall, thinner, and vertical is the best shape for brewing vessels because the aeration rises (gravity) allowing more bang for the peso.

Plain old aquarium bubblers with multiple hoses works best for me. (I don't use those damned diffuser things on the end of the hoses).

CarlosDanger.

CarlosDanger. (love the period) I was hesitant to answer a few posts lately. I know the answer but was afraid saying the answer in my usual way would bring down the house. But I saw you took point one one today so I thought I could venture forth and take point on the other. Less fronts is a good thing. Thanks for the support.

"more bang for the peso" he he.

"(I don't use those damned diffuser things on the end of the hoses)." as also do not many experienced aquarists. Pretty bubbles one might want in an aquarium display are not needed for our purposes of brewing tea the bubbles, diffuser stones are also not needed for moving the bottom water to the top and the top water to the bottom of the water column, or even for aquarium survival purposes but are purely ascetic which is why many love the effect of bubles. Who doesn't like a little bubblie from time to time.