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Thread: UAS: Down to the nitty gritty. Lets discuss the known and speculative minute details of the concept

  1. #1

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    UAS: Down to the nitty gritty. Lets discuss the known and speculative minute details of the concept

    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.

  2. #2

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    Hmm, vertical dump bucket scrubber. Could use it for wave action too...

  3. #3

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    If it is easy to build you can try one but I think It would be very diffucult to built/maintain. I see more potencial to changing bubble size but Im not an expert.

    One of the "advantages" of UAS is that it is very easy to build compared to the previous waterfall version. At the begining of UAS when Santamonica was asked abaut the advantages He only said its easier to build in any sump.

    IMO a lot of things are still being studied. LEDs are very powerfull but everyone covers different screen size with each LED. Ive read from 4 sq inch to 15...

    Size of bubbles may be important but not too easy to manage for most of the people. If you post how to make golf ball sized bubbles I can try that in one half of my screen and post results (as long as it is easy to build and maintain).

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    Quote Originally Posted by Gigaahxl View Post
    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.
    I think I was sort of doing this. One of my attempted solutions on my UAS was to wrap the screen with a piece of plastic like a report cover, it wrapped around the bubble wand so that it forced the bubbles to make contact with the screen (mine weren't) and this made the algae really grow well on the screen but my nutrients rose, so I figured it was blocking water from getting to the algae, so I removed it. But nutrients never came down after that so it wasn't that.

    Now if you took that idea and made it 2 split pieces of clear plastic or a chamber almost, like a zip-lock bag with the top and bottom cut off and slid down over the screen, held open at the bottom but free to move above that, and then pushed enough air into the bottom, this would in essence convect water up through the bag quickly, and I suppose with enough air flow or the right material (bag material) then you could fill the whole area around the UAS with air quickly and this would be followed by a rush of water. Or maybe not. I don't know.

    I think the fault of the UAS honestly is water flow. The bubble action may provide the random action needed to break the boundary layer, but the waterfall scrubber delivers the nutrients much better. The best UAS scrubber idea I have seen thusfar was the one that was a horizontal flow box using a skimmer pump on one end so that the water and bubbles were whipping the screen back and forth in the flow really randomly. That's what you need, lots of flow, and there is no way to get past that. Without turning the water over the growth substrate at a high rate, you will not get effective filtering. So the UAS is great for a smaller system that does not have much volume to turn over, because it can keep up. Put it on a larger system and it grows great but just doesn't cut it. So you need a large area to put it, and you need a lot of flow across it. Lots of flow + lots of bubbles = the need for a bubble removing method, so you really have just traded one set of complications for another.

    I'm not completely discounting the UAS, but I am just not all hyped up about it. I think it's different but not any better or worse at this point.

  5. #5

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    How abaut separating the screen from the airstone?

    Im just starting to see growth in my LED scrubber but it seems to be yellow indicating strong light or reduced flow (despite I cover 4 sq inch with each 3W LED running at 2W). I was thinking of separating the screen from the bottom and leaving one or two inches in the top. I used some airlift pumps and they are very efficient. Yo just need to avoid any interference.



    I made a "screen holder" where I can place the airstone in the bottom. Then I can place the screen 1 or 2 inch from the bottom. Ill try it and Ill post a picture if it works.

  6. #6

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    I agree with the not being sold on the UAS *asis* as far as comparative effectiveness. The I just started with them..my jury is still out. That being said. There is no doubt is has advantages in cost, and size, and ability to "go where no scrubber has gone before. A water fall scrubber can certainly be small for example my custom AIO 0.9 gallon tank but it's not easy with nooverflow and still keep it clean. I threw together a uas in a few minutes for a beta tank using a micro hob filter.. It just happened to be clear but it's not hard to cut a hole in a black one and put even a piece of old plastic packaging in place.

    My brain lives for improving and designing new things. I get a feel it's a matter of hashing out the right design to get the effectiveness part of the UAS more firm and fool proof. I have a couple concept ideas to improve the perceived or actual weaknesses of the UAS: bubbles and water flow. With some work they could even wind up being being easy to build.

    I'm still tinkering with making the uumm LBG rofl Large Bubble Generator. It's not simple and easy enough enough yet. But if you want to mess around with large bubbles the easiest way off the top of my head is cut a 2" x 4" pieces of clear plastic (like packaging from something you got at the store). Fold it long ways into a very shape and put hot glue on the ends so it would float like a boat hull. Put an airline inside the "V" at the peak. The submerse it point up. If your pump flow is really high you might need to dial it down. With it under water in your hand start from level and try different but very slight angles. Maybe not the most useful way of doing it but it let's you see an easy way of making BF bubbles.

  7. #7

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    That's the root concept of some of my ideas. You can gain flow by just putting a little thought into the idea that you want to intentially direct the flow of water in and out of the device and direct as much of the energy and displacement of the bubbles into conveying the water as rapidly as possible past the screen.

    I can tell you with certainty with the right design and the right bubble you can envelope the entire width of a reasonable size screen and move a good amount of water potentially envelope an entire screen height as well. I've also been experimenting with cleaving bubbles with the screen. Interesting and fun stuff. there is a lot of room in the UAS for inventive design.

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