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View Full Version : Anyone turn a bio-wheel filter into an algae scrubber?



powers2001
01-30-2010, 08:11 PM
Anyone turn a bio-wheel filter into an algae scrubber?

I know very little about AS's, but I am excited about them and I'm wondering if this would work. :geek:

kcress
01-30-2010, 11:37 PM
People have talked about it but I've not seen one.
They would have a lot of advantages if they could be made to work.
Give it a shot.

SantaMonica
01-31-2010, 07:44 AM
You can try it. Nobody has. Do it for fun only, not for results.

inkidu
01-31-2010, 12:54 PM
I don't know if this will help. Its a patent for a "An improved algae scrubber system having a partially submerged rotatable drum (16) wrapped in plastic mesh or algae screen"


http://www.freepatentsonline.com/6837991.html

I kind of like the idea of it passing by some intense leds.

Maybe also if the water it was passing through had a fairly large amount of air running through it.

Setup a situation with a small boundary layer?

Could buy some fairly expensive but very specific wavelength leds and make a very small setup for a nano ???

Just suggestions hope this helps.

SantaMonica
01-31-2010, 07:53 PM
Search for the "Eco Wheel".

AlgaeNator
01-31-2010, 11:11 PM
Wouldnt the Algae get dizzy going round and around? hehehe

I would think larg GHA clumps would also want to TEAR off the drum easily, and it would have turn slowly...

Then there is the issue of lop sidedness of the drum, where the weight isn't balanced well on the drum, when the Algae grows thicker on one side than the other..or unevenly the drum might stall. If it does move it might really throw water around too like a wet towel ahaha... Unless you can get it to grow evenly somehow, that might be a CON to the idea.

However I really like the idea of a drum only because watering it would be so much easier... you move/spray it with water and also design it so it's slightly submerged constantly also watering it.

Not sure how fast you want it rotating.. My first thought was to power it with water movement ONLY, but more I think about it, the more I think a CONTROLLED Rotation using a small slow turning high torque mechanical motor on the drum (s), This might be the way since you can generate slow even speed but with torque on it. This means even if the drum wasn't well balanced it would still turn at a nice even slow pace regardless due to the TORQUE of the motor.

Another thing you will need is material that the Algae can cling to very well, which you can wrap around the drum. (Which I have discovered already) :)
So Check there.. lol...

As far as lighting the algae would have periods no light on it for a few seconds I guess.. not sure it matters but it would be like like a strobe effect where the light wont hit it, then it will. I guess that would simulate a few clouds blocking it as in nature.. Put the lights on TDC, On each side at 3 and 9 O"Clock that would cover the exposed drum screen fairly well I would think

One last thought is, the SURFACE area might be reduced minimized when using a drum, esp if you were using only ONE drum that is unless it was LONG and large or multiples of them. Compared to our current screens I would think you would need to have it made larger or just have a few of them..going... Would have to see how many and how large of a Wheel/Drum could be created and turned for under sump use.. Might be able to make a pretty good sized one.. or several smaller ones... Which might be doable. mmmmm

Could also set the drum/wheels to be easily removable for cleaning.

Maybe I'll build one and lets see?

:)

Good Question Power 2001 !

inkidu
02-01-2010, 05:26 AM
Maybe somehow you could use a rotisserie motor with a square plastic spit although the one I use is pretty noisy but it is very old.

Slow with lots of torque.

Hope this helps

kcress
02-01-2010, 11:38 AM
This would definitely be a good app for LEDs as all other lighting sources would couple horridly with a cylinder. Picture a bulb over it. Only a narrow strip would be brightly lit while all the other photons would blow away in other directions. You would want very directional light.

powers2001
02-01-2010, 09:25 PM
How about using the filter's pump impeller to turn the wheel somehow?

Also the drum in an oceansmotions. I have one I might sell.

Amphiprion
02-01-2010, 10:49 PM
Get enough water flow running past it and it should turn itself, as long as it is able to freely rotate. No complex mechanisms should be necessary. The only thing I am unsure of is how readily could it turn once it has become covered with algae.

AlgaeNator
02-02-2010, 03:56 AM
though water powered wheel is tempting for its simplicity.. I think you would need:

1. LOT of water to move a grown out drum/screen... and

B. It would have to also be moving pretty quickly too.. Then drum would quickly become unbalanced.. heavy too...and even if you got the drum to turn, it would require quite a bit of flow, then it would also SPLASH like crazy... as the GHA grabs water and flips it up and around.


Having a small powerful Slow turn 12V motor or some such like the guy mentioned above, Rotisserie motor would work.. U would want to turn it slow but under power/torque.

rygh
02-02-2010, 09:49 AM
I researched the eco-wheel last night.
What they do is have an upside-down paddle wheel essentially, driven by air.
And it really seems like a great way to do it.
The air bubbles rise up under one side of the wheel. It gets caught in the paddles, and slowly displaces more and more water.
This then forces the paddles up, and so on.
Given the density of water, that can produce a LOT of torque to turn the wheel.
The paddles also act to slow it down, in case growth is lopsided, and cause it to sometimes turn on its own.
And it means no pumps to generate more heat in the system.

There are some informative patents on it. Seems to be abandoned though. Looks like the owner is
concentrating on large industrial versions. The original eco-wheel was $3000.

As a bouns, they run the air through a tube. This acts as a mini protein skimmer, which
will increase the nutrients on the algae, as bubbles brink it up to the wheel.
However, I am not so sure about that logic, since I don't think those proteins are quite in the right form for
algae to use directly. Too large.

It seems like it might be possible to build one of these wheels very cheaply, with simple irrigation pipe.
Fun for tinkering.

SantaMonica
02-02-2010, 10:34 AM
As a bouns, they run the air through a tube. This acts as a mini protein skimmer, which
will increase the nutrients on the algae, as bubbles brink it up to the wheel.
However, I am not so sure about that logic, since I don't think those proteins are quite in the right form for
algae to use directly. Too large.

Not too large; instead it is too organic. Algae does not eat organic, so anything delivered to the algae by a skimmer will just be clogging the algae up.

rygh
02-02-2010, 11:57 AM
Some quick calculations, assuming my cheap pipe idea.
Basically, make a circle of a lot pipes that are cut in half.

You can make a 6" x 4" wheel, using 1" pipe, with about 100 sq in of useful surface area.
But there is only about 1/4 lb of lift from air, so might stop.

You can make a 12"x6" wheel, using 1.5" pipe, with about 400 sq in of useful surface area.
There is about 1.5 lbs of lift from air, so probably ok.

However, by adding more pipe specifically for the air, you can increase the force a lot.
So viable, but not as easy or powerful as expected.
Oh, and there are huge guesses in lift calculations. Could be off by 2X.

I am thinking the powerhead idea might be better. Maybe both.
External motor is fairly hard to connect. DIY bushings or pulleys can be a real mess in all that water.

But it is interesting how quickly you can get a LOT of surface area with a fairly small wheel.

powers2001
02-03-2010, 10:17 PM
What ever method of turning the wheel, the drum will have to be maintained to keep it from being lobsided. Picking out clumps of turf algae to balance the wheel. This picked out stuff can then be fed to herbivorous fish and inverts.

kcress
02-04-2010, 03:11 PM
If you turn it with a gear motor like a rotisserie then balance is not important. You could strap a brick on one side.

I suspect the right speed would be whatever it takes to have the algae out of the water no more than a few seconds as once the water has drained no more nutrient exchange is happening.

rygh
02-04-2010, 04:51 PM
From reading about the eco-wheel, it was 2 RPM.
So out of the water for 60 sec /2 rpm /2 half out = 15 seconds.

While nutrient import would be off if out of the water, CO2 intake might be great.
Getting CO2 from the atmosphere is far easier.
From memory reading about freshwater planted aquariums, CO2 was far more important than nutrients.
However, salt water has a ton of CO2. So not really sure about that chemistry.
Perhaps getting rid of O2 is limiting.
In fact, I wonder if that might be part of the reason why the vertical scrubbers work better than horizontal.
The vertical water layer is really thin (limited by physics, not flow), possibly allowing much better air diffusion.

The big problem with motors for this:
An axle connected to a gear motor is not that easy.
- You need to seal the motor, and any metal parts, fully from the water. So sealed bushings/bearings.
- You have to remove the wheel for cleaning every week. Which means taking apart sealed bushings/bearings.
Using a belt, or making the wheel a "gear", is not so easy either.
- The wheel and everything near it will get full of slippery gooey gunk.
It can work, such as removing the whole assembly or something. But a pain.

Air and powerhead seem the best to me.

SantaMonica
02-04-2010, 06:59 PM
Getting CO2 from the atmosphere is far easier.

Yes but algae only get if from the water.


The vertical water layer is really thin (limited by physics, not flow), possibly allowing much better air diffusion.

It's better because the swift flow reduces the boundary layer on the algae. The flow rate at the boundary layer is several feet per second.

rygh
02-05-2010, 10:50 AM
Getting CO2 from the atmosphere is far easier.
Yes but algae only get if from the water.
Sure, when they are IN the water.
When out of the water, as when on the wheel, CO2 should have no problem diffusing through cell membrane. (aka lichen)
In fact it might be easier, since it is less locked into carbonate/bicarbonate.
But it has been too long since organic chemistry to remember all that.

But what I am really trying to figure out here is if there is some advantage to a bio-wheel (eco-wheel) approach.
The CO2 and other oddities are probably a non issue, if nothing else, because it is only 15 seconds above water.

I think the only real advantage is the elimination of a big water pump, and reduction in vertical height requirements.
A simple air pump can drive it, and a 12" wheel only takes 6" above (and below) sump water level.
Not bad, even if it results in less efficient nutrient export.

Also, the sump return may drive it, if it falls on it, much like a regular water wheel.

SantaMonica
02-05-2010, 11:55 AM
When out of the water, as when on the wheel, CO2 should have no problem diffusing through cell membrane.

My reading of algae metabolism seemed to show that most algae did/could not do anything while in air. There were a limited number of out-of-water turfs that did a little with the air, but not much/many.


But what I am really trying to figure out here is if there is some advantage to a bio-wheel (eco-wheel) approach.

None really. Has been covered before.


I think the only real advantage is the elimination of a big water pump, and reduction in vertical height requirements.

No pump is needed if fed by overflow. And a wheel would most certainly be taller than a wide, short scrubber, which is how they should be shaped for high performance (which is presumably what you would be looking for in a wheel).

Biggest problem of a wheel: hard to diy. Has never been done that I know of.

kcress
02-05-2010, 02:10 PM
No matter how you cut it horizontal or vertical scrubbers end up with water spritz hitting everything around. Those lead to growth where you don't want it. You also always have some noise from rapidly flowing water. You need a pump - somewhere. As for the algae you have that drat boundary layer.

A wheel style would require no pump anywhere.
No splashing.
No noise.
And the major point would be elimination of the boundary layer as the surface would briefly "drain down" every rotation.

rygh; The CO2 is dissolved as a gas in the water. This is where the algae extracts it from. Not across the flowing barrier the water presents. The higher levels of CO2 would be from the life processes in the tank not in the surrounding air. CO2 would actually be transported out of the tank water into the air on the rapidly moving surface flow.

One RPM would probably work OK. There are many gear motors with crazy torque available with 1RPM - (think second hand).
http://cgi.ebay.com/SYNCHRON-1RPM-Motor ... 20af55015f (http://cgi.ebay.com/SYNCHRON-1RPM-Motor-and-Clock-Mechanism-610-110V-3W_W0QQitemZ140380537183QQcmdZViewItemQQptZLH_Defa ultDomain_0?hash=item20af55015f)