Most efficient DIY needle wheel?

scottward

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Oct 26, 2007
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In conjunction with an AM1000, I have CO2 misting through a powerhead/spray bar in my 100g tank.

I am feeding CO2 directly into the impellor chamber (i.e. via the pump intake), and allowing it to push the mist down a spray bar and into the thickest parts of my tank. So far so good.

I was thinking of swapping the standard impellor for a 'needle wheel version', but there isn't such a thing for this brand of powerhead (Resun 3800sp).

So, I was thinking of buying another normal impellor and DIY'ing a needle wheel.

I have read the threads in the past, the hot nail trick, the 'furring' up etc.

I was wondering, what is the most efficient way of making a needle wheel - not necessarily the quickest?

I have a dremel - would perhaps cutting small slots along the top/bottom of each blade be the way to go? I think that the slots should not be in exactly the same place on adjacent blades? How many slots etc?

Is the time spend converting a standard impellor into a needle wheel version going to be worth it? My understanding is that it makes the bubbles considerably finer, and, the finer the bubbles, the easier they disolve and are therefore utilised by the plants??
 

shoggoth43

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If you want a very good method for this you may want to look up the mesh mods the reefers use. They will tie material like enkamat or similar onto the impeller to cut up the bubbles. The major problems with this method are that the mesh will wear out as it tends to rub on the inside of the volute, and you will have less flow through the pump. How much less flow and how often to replace it are things you would have to find out the hard way. The size of the bubbles you'll get will be considerably smaller however so it may be worth trying. The mesh may not be easy for you to source, although I have seen "kits" available for a reasonable price ( for here anyway ).

-
S
 

mi5haha

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you can use king2 needle wheel type pump directly. it is 20W power output, with good water inlet, air sucking on water inlet, and water outlet fitting, so this can be place outside the tank (dry running) if it is linked with a sponge filter. bubbles are so small.
 

scottward

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Oct 26, 2007
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I suppose it's all about the efficiency/flow rate trade off.

If I could modify my impellor such that each blade looked like the mouth of a beleen whale, sure, I'd get excellent CO2 dissolving, but at a huge cost to flow rate (and would clog up more easily). On the other hand, a few holes burned/drilled into each blade won't be quite as good at chopping up and dissolving the CO2 as the 'baleen' version, but is still better than no holes at all, yet still provides good flow and doesn't clog easily.

So for me, the decision comes down to making holes in the blades, cutting slots in the blade, or snipping the blades down the centreline.

All methods are fine for me to do, I have a dremel, very small drill bits etc.

Tom indicated that he has found snipping the blades down the centreline to be the most effective, but I have heard others say that they have had problems doing this due to the blades not staying put once they have been bent etc. I suppose different brands of impellors, different thicknesses etc, play a big part in what works/doesn't work.

So, I'm thinking the most sure fire thing for me to do is to take the impellor, and just drill (or I might melt) a series of holes down the centre line of each blade, slightly staggering them between blades. I've read enough on here to indicate that this should work and is easy to do.

I could snip the blades but there is a risk that I might not be able to bend them very well (i.e. I might be one of the people that isn't successful with this method).

I could cut slots into the blade with the dremel but this seems more fiddly and probably wouldn't be any better than putting holes in the middle.

Attaching mesh etc to the blade seems, from what I have read, to cause more trouble than it's worth, due to clogging etc. I don't want something I have to clean all the time.

So - would the general consensus be to drill holes? Easiest? Most risk free? Zero maintenace (i.e. no cleaning)?

Scott.
 

Gerryd

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Hi Scott,

From my reading it appears that both methods work very well. I think it lends itself well to experimentation with fuzzing it up, etc. Different materials, etc.

I just now finished a temp install of a DIY needle wheel on my 180 gal. Here are the specs:

Current c02 method: Mazzei 584
New c02 method: Rio 1000
DIY method: Center cut and bend

I just cut down the center about 70% of each blade using a small pair of wire snips. I gently bent each one back away from each other. The 'tops' pointed one way and the 'bottoms' pointed the other. I can see where the 'bends' may straighten out over time....it will become part of the general maintenance I guess like cleaning a disc...:)

I mounted the Rio sideways in the tank on one end below the MP20. I mounted the c02 line about 1-2" BELOW the Rio intake so the c02 bubbles get scarfed (a technical term) right into the intake.

Result:

Very nice mist. Certainly comparable to what my mazzei provides. Flow seems fine but not as good as new. It DOES make a bit of a popping sound when the c02 bubbles are chopped but silent with c02 OFF. You have to be close to the tank wall to hear it...

I lowered the bubble rate as if too fast bubble build up and escape out the intake on the 'top' side....

So, I will adjust/monitor/compare using this method to the mazzei and see how it goes.

I will report my progress...

I do have several questions however.

All,

1. What seems to be the best way to introduce the c02 to the pump? Simply drill into the outer casing so I can slip the c02 tube inside? Or is my current placement/method viable?

Tom,

1. On your 180 are you ONLY using a DIY Rio 1000 series for c02 injection? Or in conjunction with a disc?
2. How do you direct the Rio c02 flow? Out into the general tank to get picked up by the current?
3. What bubble rate do you feed into the Rio?

I had previously modded a Mag 500gph with the drill holes in the blade method. It did not work that well for me but I may also be an idiot....I have about 4-5 holes in each blade and I staggered them up/down...

Thanks in advance.
 
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scottward

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Oct 26, 2007
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Hi Gerry,

Thanks for your feedback; appreciate it.

I know if I put some questions here somebody reading this might reply to my questions and miss yours. I will put a reminder at the bottom...

I have some questions for you Gerry:

- I wonder if cutting through 70%, or all the way to the root of the impellor makes much difference? With respect to both the 'chopping' ability and the possibility of the blades slowly moving back to their starting position.
- I wonder if the thinner blades would suffer from flexing and eventually snap off at the point of bend? I think holes drilled would be less likely to suffer from 'plastic fatigue'.
- Did you note what the mist output was like on the Rio 1000 before you did the mod?
- Is the mist so fine that the bubbles don't float to the top any more?
- With your Mag 500gph where the experiment with the holes didn't work out (I do remember reading your posts about it a long time ago), what was the reason it didn't work out? Was the mist not fine enough? Was it just the particular type of powerhead?

And my answer to your 'All' question
- What about connecting an airstone to the CO2 line such that rather than single noisy bubbles moving into the impellor chamber a more steady stream of smaller bubbles is introduced? I guess the downside of this is that airstones can clog up.


And I'll add another 'All' question
- holes vs snipping the blades; I think I can appreciate why the blade snipping would in theory work better, we're creating more pathways for water/bubbles inside the impellor chamber (i.e. water/bubbles stay in the impellor chamber longer hence reduced flowrate). Is that correct?

** Note Gerry's questions in the previous post, I've just 'tacked' onto his list ** :)
 

Tom Barr

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Gerryd;52287 said:
Tom,

1. On your 180 are you ONLY using a DIY Rio 1000 series for c02 injection? Or in conjunction with a disc?
2. How do you direct the Rio c02 flow? Out into the general tank to get picked up by the current?
3. What bubble rate do you feed into the Rio?

.

I use a Rio 1000 on my 180, I do this:

resizedDIYneedlewheel2.jpg

needlewheelDIY1.jpg



So I went from 5 blades to => 15 thin small blades, bending them back to get more distance between them.

This makes hardly any sound and makes a very slight haze from mist that's tough to see/notice.
This tank also does the best over time vs the disc and reactor method sI have on other tanks.
I'll likely switch to this for all the tanks since I use small rios or other supplemental flow.

I've tended to do longer term test recently and this one passes the muster.

I direct the flow in the lower corner along the back wall the length of the tank, this hides to powerhead and gives the longest fetch for the mist/gas dispersion.

The bubble rate is pretty fast, dependent on the tube sizing.
Maybe 4-5 a second? I have venier handles and use those and slow adjustment, not bubbles per second.

Impellers are cheap and easy to buy new ones for Rios, so fear not.

Regards,
Tom Barr
 

Oreo

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May 6, 2010
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Why do you feel this method is better then using a reactor Tom? Have you been unable to achieve 30ppm+ using reactors? Or do you think the plants actually benefit from having CO2 bubbles in the water vs. just dissolved CO2? Some other reason?
 

scottward

Guru Class Expert
Oct 26, 2007
958
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Brisbane, Australia
Hi Tom,

The Rio 1000 that you are using, is that this? http://www.aquacave.com/rio-hyperflow-8hf-br-water-pump-2042.html

So it's 1000lph? About 500gph?

And that is the only thing you are using in the 180 gallon tank - it doesn't seem like enough? And at only about 5bps you must get excellent milleage on the 15lb bottle (from memory you are using a 15lb bottle).

And no spray bar connected to the output? Just point it along the back glass and that's it?

I think it's time for me to get out the snips!

Scott.
 

Gerryd

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Hi all,

So I went from 5 blades to => 15 thin small blades, bending them back to get more distance between them. The bubble rate is pretty fast, dependent on the tube sizing.
Maybe 4-5 a second? I have venier handles and use those and slow adjustment, not bubbles per second.

Tom,

Splitting the five blades comes to 10 smaller blades. Did I miss something to get to 15?

Even with different tubing and a nice needle valve, you still get a certain bubble rate no? Even if the bubble is smaller/larger based on tube size and you have a $1,000 needle valve it will still produce a bubble rate correct? Or does the nicer valve work differently somehow? What am I missing here?

Scott,

I am just using the Rio 1000+ rated at only 271 gph at 0 head.....

http://www.bigalsonline.com/BigAlsUS/ctl3684/cp48947/si1382144/cl0/rioplus1000pumppowerheadul

I think I need to get the one you linked too...I didn't realize there was more than one model 1000.

I also noticed that my impeller is smaller/thinner than the one in Tom's pic....assuming it is also a Rio impeller.

I bet the larger flow makes a bigger difference as my pump only makes it halfway across the tank before it starts to peter out....
 
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Gerryd

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scottward;52295 said:
- I wonder if cutting through 70%, or all the way to the root of the impellor makes much difference? With respect to both the 'chopping' ability and the possibility of the blades slowly moving back to their starting position.
- I wonder if the thinner blades would suffer from flexing and eventually snap off at the point of bend? I think holes drilled would be less likely to suffer from 'plastic fatigue'.
- Did you note what the mist output was like on the Rio 1000 before you did the mod?
- Is the mist so fine that the bubbles don't float to the top any more?
- With your Mag 500gph where the experiment with the holes didn't work out (I do remember reading your posts about it a long time ago), what was the reason it didn't work out? Was the mist not fine enough? Was it just the particular type of powerhead?

And my answer to your 'All' question
- What about connecting an airstone to the CO2 line such that rather than single noisy bubbles moving into the impellor chamber a more steady stream of smaller bubbles is introduced? I guess the downside of this is that airstones can clog up.


And I'll add another 'All' question
- holes vs snipping the blades; I think I can appreciate why the blade snipping would in theory work better, we're creating more pathways for water/bubbles inside the impellor chamber (i.e. water/bubbles stay in the impellor chamber longer hence reduced flowrate). Is that correct?

Hi Scott,

1. The 70% cut was simply because I cut the first blade too far to one side and it splintered kinda like wood does. I got scared and thought that cutting to the end would make them too brittle and break...not sure if this could happen but the blades on this Rio model are very thin...not like the Mag impellers which are much heavier/larger.
2. I could agree with this.
3. Sorry I did not. Just comparing to the mazzei :)
4. Mostly very fine mist. However this gets caught in the current and flows all over. It will still float to the top even if mist...
5. Can't even remember now. I think I still have it and will experiment again and let you know....

Thanks,
 
C

csmith

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Hey Gerryd,

Gerryd;52287 said:
1. What seems to be the best way to introduce the c02 to the pump? Simply drill into the outer casing so I can slip the c02 tube inside? Or is my current placement/method viable?
You've done what I do. My CO2 line is attached to the glass 1-2" under the powerhead via suction cups. I don't lose bubbles out the back and it works well. No real reason for not inserting it into the powerhead itself, just lazy I guess.

Gerryd;52287 said:
I had previously modded a Mag 500gph with the drill holes in the blade method. It did not work that well for me but I may also be an idiot....I have about 4-5 holes in each blade and I staggered them up/down...
I have a mini-jet 404, so snipping the blades was out of the question. I took a sewing needle, heated the tip and shoved it through the blades. I can't give a definitive amount of holes I made as I just went until I thought one more might be too much. The holes left from the needle were tiny and they eat the CO2 bubbles up incredibly well. Maybe try smaller holes?

Gerryd;52310 said:
Even with different tubing and a nice needle valve, you still get a certain bubble rate no? Even if the bubble is smaller/larger based on tube size and you have a $1,000 needle valve it will still produce a bubble rate correct? Or does the nicer valve work differently somehow? What am I missing here?
I think the answer to your question is too many bubbles come out to count accurately. That's the answer I'd have to give about my setup, anyway.
 

Gerryd

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Hi,

I apologize for monopolizing the thread...

Yes, I got the c02 line placement idea from you and others :)

I think the answer to your question is too many bubbles come out to count accurately

C,

That is exactly what I am attempting to determine. Is BPS (bubbles per second) a USEFUL term of measurement regardless of diffusion method and hardware? Or is it like watts per gallon in that it is a useless measure and comparison point among different configurations?

To me hardware can only change the size and rate of the bubble. However it still needs to come out the end of the c02 line into your diffusion method at some point. What is the rate AT THAT POINT?

Is this even comparable?

As an example if I provided even my mazzei with a 'countable' 10 bps my tank would be overrun with all types of algae and poor growth....

I need to give it 'dozens' of bbs to provide adequate c02....the stream is simply constant and not countable at all...

With the DIY mod, I am back to being able to count the bubbles. I need to start over with bubble rate as the diffusion method is different. No way I am changing that much and leave the bubble rate the same....I can live with some algae and/or poor growth while I experiment as I have done it before...

Am I making any sense?
 
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C

csmith

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Yes, you're making sense. WPG isn't useable because it's not an accurate method at all. BPS can be incredibly accurate, but I've been taught recently that sometimes absolute accuracy isn't all that necessary. In my case, coming up with an equation to figure the amount of K given from KH2PO4 isn't needed as when you add enough KNO3 you more often than not have enough K. In this case, BPS doesn't really mean much due to, as you pointed out, the diffusion method changes the bubble rate needed by quite a bit. If the answer can change by a large margin then why search for the most accurate answer? For me, dose KNO3 and KH2PO4 and don't sweat it anymore. For this, why worry about how many bubbles are coming out of the tube? How much CO2 do we need? Enough. No bubble rate can really dictate what enough is from tank to tank.

Holy crap, I've learned something.
 

Gerryd

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C,

Glad your brain functions on Friday night :)

What you say makes sense..

BUT

Since I am now emulating THE SAME setup as Tom (that is the goal anyway), the bubble rate is more important no?

Since the pump is really independant of other plumbing as it is stand alone, I think that bubble rate comparison is more worthwhile...

I figure that if person X can use method Y on a tank of N gallons and use a bubble rate of Z and get results like Tom, than I can use their rate as a BENCHMARK of sorts.

I am never sure of this anymore as Tom told me long ago 'don't believe everything you THINK' which I think is pretty good advice..

I know about your desire to measure macros to the nth degree, but c02 is not as easily administered to have 'enough' as you well know :) More Macros can just be dumped in with little thought up to a point. Not advocating fert overdosing....

Not so with c02...

Thanks for the help.
 
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shoggoth43

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BPS as a measure is only useful for YOUR equipment and as a general relative measure for changes you've made. I run at 15 PSI 2nd stage, but there's no back pressure in the delivery tube as I feed right into the pump. I set it for say 4 BPS and go from there. However, if I put on a ceramic disc I have much more back pressure and now I have to crank up the amount going in to get the same BPS, but it won't deliver the same amount of CO2. Tubing size may also increase the size of the bubbles coming out depending on your equipment. There's also the question of what tubing you use and how long it is.

Basically unless what you do is very similar to what I do, chances are that my 4 BPS is not really the same as your 4 BPS. Also, how you feed your CO2 in and how you mix it in the tank may make your setup much more efficient than mine, so the 4 BPS you put in may end up in the tank better and longer than mine. Alternately maybe the fact that mine mists differently than yours may make mine more efficient for the plants and bioload that I have. Lots of variables and maybe not really the best measure of success but it's useful for when you make changes.

-
S
 

Tom Barr

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While never sure, you can try and see if you can really know something, even if limited and narrow, then look elsewhere for more little nuggets knowledge.

As long as you have some sort of a relative measure, do not trust absolute ppms etc..........then you can work well with it.
I have 5 tanks, each is different, so I have 5 different relative measures.

Regards,
Tom Barr
 

scottward

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Is there a way I can attach an image on here without having to link to it somewhere (e.g. photobucket). I just have the image on my hard drive - can I just attach it to this thread somehow?
 

scottward

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I read through the above posts which were interesting to read, but I don't really have anything to add myself. ;-) This is my first go at DIY'ing a 'needle' wheel, hopefully I will have something to add soon as I experiment.

I took the impellor out of my Resun 2000lph (it is a 6 blader).

I was going to snip the blades but decided for my first go I would just drill some holes.

So, I started off by drilling 2 larger holes on each blade and then drilled smaller hole in between the two. I just guessed where to drill them, no measuring or anything.

I could easily fit more little holes onto each blade, and I probably will drill more holes, but not just yet.

I re-assembled the powerhead with the modified impellor and got it running again.

I can still see the bubbles coming out of the powerhead, but I'm pretty sure they are smaller than what I had before. The bubbles still rise to the surface but appear to be more easily influenced by the current in the tank now, such that they generally have a hard time making it to the surface.

Plenty of flow still. I think I could drill several more holes in each blade, a 'swiss cheese' look.

Attached are some photos.

Hmmm. So Tom gets his mist so fine that he can hardly see it. Do you have good eyesite Tom? ;-)

I can hear the bubbles ticking into mine, an audible bubble counter. Probably about ~4bps at the moment. AM1000 is still cranking away at the same time, can't count the bubbles going into it, too fast.

Will observer and report before making any further changes.

Gerry - how's yours looking?

Scott.

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