Have a seat and put your reading glasses on...

I'm leaning on anyone that has details on the up flow bubble scrubber design. SantaMonica this would be the place to spew out all the bits of information you've learned. I'm the kind of guy that has to know exactly how any why something works and enough of the micro detail to make intelligent descisons on the design of each aspect of something.

I went to go build a uas. While the first standard build version looked like it worked on par with the examples and guidlines . getting the bubble bar working was more challenging than I expected. As was getting the bubbles to stick to the screen. In all with the methods I came across I never was fully content with bubble size and how they interacted with the screen given the current ideal model of bubble/screen collision.

This led me down a long path of researching the science of bubbles, how they form, and what makes them larger and smaller. It was facinating....no...really I swear...OK so it was pretty boring. BUT I learned enough to make bubbles any size. I was able to easily make bubbles ranging from the size of a pea to larger than a golf ball in just 8 inches of freshwater. Bigger isn't difficult.

After tackling that I spent some time going over basic redesign of my constantly morphing concept/prototype UAS to make it function more efficiently and contact more screen with one large bubble and get it moving more water as well(like the air pump powered under gravel filter or aqua lifter). This change made me happy as water flow had been cited as a potential growth factor.

From there I moved on to and conquered producing several bubble streams of golf ball sized bubbles.

This is the point where needing to understand the inner details of bubble scrubber in order.
You can make any bubble size with any pump. It boils down to how frequently these large bubbles are produced.

So the question burning here for me is this. Is there any information of any sort anecdotal or factual indicating whether say..a bunch of marble sized bubbles(which are harder to stick to the screen) or a few golf ball sized bubbles is a better option? How fast the algae absorbs the nutrients in its boundary layer? An idea of wet vs dry time ratio?

I have NO idea.
But as I mulled that over in my head another concept entered my mind. It may or my not be a viable alternative as I havt hashed out much detail wise. But what if you used the bubbles run up the screen to fill the cavity the screen is housed in then dumped the air resubmerging the screen completely again? Basicly just pumping the water out exposing the screen until the full screen is exposed to air then let the water back in by letting the air out. Short maybe not enough water flow..maybe to much air exposure...but then again maybe not...a vertical version of the old tilt table algaescrubber.

Ill post more later. sorry if some of this is fragmented. Did it on my tablet after a long day. If any thing I said doesn't make sense ask and I'll clarify. I have to go. I'll check back later.