Most efficient DIY needle wheel?

C

csmith

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Here's what I've done. First picture is for size reference of the blades, second is a close up. Lots of small holes is, personally, what I think makes this work. The "strings" hanging off are just melted plastic from when I made the holes, a razor blade can be used to remove the excess.

NeedlewheelMod2.jpg


NeedlewheelMod1.jpg
 

scottward

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Oct 26, 2007
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Cool, thanks for putting up some pics as well. I suppose as many holes as you can get in the impellor blades the better. And to counter the reduction in flow simply choose an overpowered powerhead in the first place.

I think I will get mine back out on the weekend and drill as many holes as I can into each blade. Lots of small holes I think.

I could have snipped it but I was worried about cracking it. I don't have a spare impellor.

I can still see my bubbles, so I guess I still have some work to do.

Is that really the ultimate - i.e. in answering the original reason for me creating this thread - the most efficient DIY needle wheel is the one whereby the output bubles are just so fine that they can hardly be seen (or cannot be seen at all)?

I understand through discussion with Biollante that the most useful CO2 bubbles are the ones that we cannot see with the naked eye?

The bubbles we can see are more or less useless?

Scott.
 

shoggoth43

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Yes and no. The bubbles you can see are still useful if they are floating around the water column and/or stuck to the plants since they can still dissolve. If they're heading right for the surface and staying there/popping then it's more likely you are just wasting your time and CO2.

-
S
 

scottward

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Thanks shoggoth.

I wonder, with dissolved CO2 in the water and tiny bubble of CO2, does the plant have to use diferent mechanisms to utilise the disolved CO2 versus the bubbles of CO2 that might come to rest on the leaves? I wonder if using a reactor and misting at the same time could confuse the mechanisms of the plant in any way and actually make growth worse?

I am using my AM1000 like normal at the moment and misting throught a powerhead - do you guys think that it is ok that I am doing this?

It's too early for me to say how well this is working out, as I've only recently starting seriously misting with a DIY needle wheel.

Gees I'm chewing through the gas though, which I don't like at all.

Maybe 2 AM1000's would be just as good, much more efficient on gas I think.
 

shoggoth43

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Different theories on this one. One is that the CO2 sticking to the plant is very similar to the plant being emmersed ( i.e. in air ) and thus has easier access to the CO2 so that you could use less of it by having the CO2 "stick" to the plant and not get dissolved in the water only to have it blow off at the surface. Dissolved CO2 would have to be extracted / absorbed by the plant at a slower rate due to less of it being available. At least that's the theory. I know Biollante likes the reactor types for efficiency.

Mixing and matching methods is perfectly fine. One think the misting method does get you is a direct method of getting the CO2 "right there" since you can blast the powerhead directly at something with a stream of mist to see what's going where. You can do similar with reactors but it's harder to do depending on the design and you of course can't "see" the CO2 enriched water or the flow/distribution around the tank.

CO2 is relatively cheap so after tinkering for a bit the amount you use should settle down once you stop playing around with the different methods. For some of us this can take months. :)

-
S

scottward;52402 said:
Thanks shoggoth.

I wonder, with dissolved CO2 in the water and tiny bubble of CO2, does the plant have to use diferent mechanisms to utilise the disolved CO2 versus the bubbles of CO2 that might come to rest on the leaves? I wonder if using a reactor and misting at the same time could confuse the mechanisms of the plant in any way and actually make growth worse?

I am using my AM1000 like normal at the moment and misting throught a powerhead - do you guys think that it is ok that I am doing this?

It's too early for me to say how well this is working out, as I've only recently starting seriously misting with a DIY needle wheel.

Gees I'm chewing through the gas though, which I don't like at all.

Maybe 2 AM1000's would be just as good, much more efficient on gas I think.
 

scottward

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Oct 26, 2007
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I've just added a bit of extra light along the back glass of my tank to encourage faster growth of my stem plants. I'm probably going to have to tweak my CO2 a bit (unless it was already plentiful). With the AM1000 and the needle wheel both running, I'm not sure whether to increase the rate into the AM1000, the needlewheel, or both! ;-) Decisions decisions.

Tonight, if I get a chance, I might pull the impellor out and drill even more holes in the blades using the smallest drill bit that I have.

Gerry, how is yours going?

CSmith - yours?

Scott.
 

Gerryd

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Scott,

So far so good! I think I may get a slighly larger model or a new impeller and try the drilling method and compare....

I just need to hide it now.....

Be careful adjusting the c02 with dual diffusion methods... very easy to gas your fish....slow and easy does it...
 

Tom Barr

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The split bade impeller is much better than the holes in the impeller FYI.
I also "furred up" an impeller a few times. I think finding a needle wheel impeller pre made or splitting the blades like I've showed is better though.
Some of the DIY mods in the reef skimmer forums are okay.

I just get ultra fine, well beyond mazzie, micro mist, I do not even see any mist/bubbles which was one of the few detractions.


Regards,
Tom Barr
 
C

csmith

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scottward;52486 said:
CSmith - yours?

Mine works well for what I need (or so I believe). I keep a constant yellow drop checker, and I've been working on my flow so I think I'm at a suitable level. As I said, though, I have pin sized (literally) holes so I get tiny, tiny bubbles if they can even be called bubbles. It's also on a 20 gallon, so the area to cover is very small. I had to go the hole route because the impeller was a bit small to cut and I'm sure the soft plastic wouldn't have held its form if I attempted to bend them. Perhaps one of those "next best option" scenarios. If you do go the hole route, the smaller seems best.
 

scottward

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So far so good! I think I may get a slighly larger model or a new impeller and try the drilling method and compare....

I just need to hide it now.....

Be careful adjusting the c02 with dual diffusion methods... very easy to gas your fish....slow and easy does it...

Cool. Thanks for the update Gerry and the advice. Yeah, I think I will tweak the AM1000 in the first instance and if it starts choking (i.e. overwhelmed) I'll push the needle wheel harder. Keep me posted on your progress.

The split bade impeller is much better than the holes in the impeller FYI.
I also "furred up" an impeller a few times. I think finding a needle wheel impeller pre made or splitting the blades like I've showed is better though.
Some of the DIY mods in the reef skimmer forums are okay.

I just get ultra fine, well beyond mazzie, micro mist, I do not even see any mist/bubbles which was one of the few detractions.

Hi Tom. Thanks for your thoughts and advice. I can see that the real efficiency thing here is all about getting the bubbles as small as possible - if they are so small that they cannot be seen then that must be the best possible outcome. What I will do is continue with my hole driling experiment to the point where it's not possible for me to put any more holes in the impellor and I will note the size of the mist. Once I have run this experiment for, say, a month or so, I will buy another impellor to suit my powerhead and split the blades as you have suggested. I will then compare the two methods and of course provide my feedback on here. The reason I went with the holes first was because there was less risk of me stuffing it up (i.e. cracking the blades or something like that).

Clearly the smaller the bubbles the better is the aim here. Cool.

Mine works well for what I need (or so I believe). I keep a constant yellow drop checker, and I've been working on my flow so I think I'm at a suitable level. As I said, though, I have pin sized (literally) holes so I get tiny, tiny bubbles if they can even be called bubbles. It's also on a 20 gallon, so the area to cover is very small. I had to go the hole route because the impeller was a bit small to cut and I'm sure the soft plastic wouldn't have held its form if I attempted to bend them. Perhaps one of those "next best option" scenarios. If you do go the hole route, the smaller seems best.

Thanks mate. Any possiblity you might get hold of a second impellor and try the cutting approach suggested by Tom? I might use a dremel to slit the blades on mine, rather than snips. Perhaps you could use something like this too? Hmmm - regarding the holding their form, that gives me a thought...

Question for Tom (+ other gurus): Once the blades have been snipped, I can understand that if they start to close back up into a single blade again, this will be counter-productive to our efforts. But - as long as they don't completely close up will they still work ok? As long as there is some kind of gap between the blades won't that be ok? As an alternative to snipping the blades, if I were to cut the blades using a dremel such that there is actually plastic removed from the blades, if they were to close up there would still be somewhat of a gap between them - this gap might still be more than enough to do the job????
 

mi5haha

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I tried Tom's way on a 18W pump. Six blades.

Blades do close back, but not into a single blade again. The issue is that the blades are very strong (they will not break), even using hot air to heat the blades split, but they will still come at least 2/3 back after a while.

The result of my test on this pump is not as good as the pump equipped with a needle wheel impellor.

I think the impellor rotating speed is also relevant if cutting the blades into half.
 

scottward

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I'm not 100% sure, but I think the impellor can turn in either direction? If the impellor always turned in one direction, I suppose we could leave one half the snipped blade where it is, and bend the other half so that it is bent in the direction where the water flow will encourage, rather than 'return', the bend.

Do impellors general spin in the same direction when the pump is turned on/off?

If so, is there any way to know which way the impellor will always spin?

Then we could just bend in the direction where the bends will be best maintained?

This sounds too easy, I'm guessing the direction of impellor rotation can change. ;-)

I've been thinking hard about holes vs snipping. Yeah, I'm starting to really think that the snipping is going to work better. Long, skinny paddles (i.e. the snipped blades) is going to allow the air/water mix to pass through more easily than holes in the blades, whereby it's more difficult for the air/water mix to squeeze through little holes.

If I get a chance, I will snip my 8-blader up tonight, turning it into a 16-blader. I was going to try to snip each blade twice but because I already have holes down the centre this isn't going to work (I think the middle blade would fall off!).

16 skinny blades in a 2000 litre per hour powerhead should do a pretty good job of chopping the bubbles up.

I tried to obtain a ready made needle wheel for my powerhead, but they don't exist, so I have no choice other than to DIY.
 

scottward

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I snipped the impellor tonight so that it is now 16 blades. I carefully bent the blades.

Doesn't appear to have made much difference, I can still see the mist.

For all the people that have made one of these, either snipping the blades or drilling holes, Tom you are the only person who has been able to make the mist so fine that it is difficult to see. Something doesn't add up...we can't all be incompetent at making something that appears so simple. ;-)

Tom - when you say you cannot see the mist coming out of it - when can you not see the mist? During the first few hours when the CO2 comes on and the CO2 is easily dissolved due to the lower CO2 concentration in the water? What about after it's been running for a good few hours, towards the end of the photo period, can you see fine bubbles coming out of it then? Also, are you feeding bubbles of CO2 into it relatively slowly, or are you hitting it with a decent bubble rate?
 

scottward

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*Bump* ;-)

Tom, I think I found the answer to one of my questions - your feeding in CO2 at about 4-5bps?

This is for your 180 gallon tank correct?

And the DIY needlewheel is the only method that you are using for CO2 for this tank correct?

Regarding the misting, can you confirm whether the misting is difficult to see at the start/end of the photoperiod? Perhaps it dissolves straight away at the start, but the mist starts to become more obvious toward the end?

I note your comment earlier about the finer the mist the better. If the mist is so fine that it cannot be seen, I assume this is because it is actually dissolving completely and there are no bubbles in the tank? Would this not defeat the purpose of having the bubbles attach themselves to the leaves of the tank? If the bubbles should ideally be contacting the leaves, isn't it possible that making the mist too fine (i.e. dissolving) could be counter-productive?

Can somebody please clarify this for me?

Scott.
 

mi5haha

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I used the real needle wheel pump. the bubbles are very fine, drifting in the tank, following the current to the other side of the two-feet tank, making their turn and going back slowly, and they are still there. They did not dissolve immediately after they are coming out the water outlet. But they do not look 'haze" yet. You can still each bubble with naked eyes.

However, cannot take photos of these fine bubbles. Guess need to use a micro-distance lense.
 
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Gerryd

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Scott,

I am just using the rio 1k split blade approach on my 180...bubble rate is more than 3-4 maybe 12-20? You will see.

Does a GREAT job so far better than the mazzei at least as far as plant growth/health shows....

I will take some pics/video later of this is operation at several bubble rates....

Will be after work my time so hope you can wait another 10-12 hours or so.....
 

scottward

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Hi Gerry.

12-20 bps? I remember you saying in other thread that your bubble rate was incredibly high. I know you can't count this fast, you just mean that the bubble rate is going nuts. ;-)

I might be confussed about what Tom is running - was he also running a Rio 1000 on a 180g like you? I'm sure, unless I'm totally misunderstaning, that he said his bubble rate was only 4-5bps (which is fairly easy to count)? Something's not adding up. You've been doing this for a while now Gerry and have a good understanding of all the principles, there is no way that Tom could have the same result as you at only 4-5bps for the same sized tank, same lighting (?). Sure every tank is difference, but within certain boundaries, things should start to form a bit of a pattern.

I must be confussed.

I shall think no more about it until I have my facts right. ;-)

I don't mind the look of the bubbles in my tank, they look cool, but I do want to get as much out of my CO2 bottle as possible (hence the reason for me creating this thread about efficiency - not ease of use, lowest cost, lowest maintence - but efficiency).

Look forward to seeing your photos Gerry.

Scott.
 

Gerryd

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Hi Scott, all,

I apologize in advance for the length of this post...

Okay. Here are three videos of my Rio 1000 with a split blade config.

The first two videos simply show the CURRENT bubble rate and mist from different angles. Can you count the bubbles per
second? I think the mist it provide is pretty darn good personally, and I have been using a mazzei for awhile now.

The third video shows the operation as I INCREASE the bubble rate significantly. At the HIGHEST rate in the video, that
was LESS than I was feeding my mazzei. More on that later.

The LOWEST rate is what I would think of as 4-6 bubbles per second.

Please note:

1. The rythmic noise from the rio. I attribute this to the shoddy DIY snipping job :) No noise with c02 off, so is useful
to know it is 'on' and getting c02 lol

2. The size increase/decrease of the mist and associated bubbles as the bubble rate changes...

Very effective method of c02 diffusion...

I will be back but wanted to post the video..

Front view of current rate and operation. Note the nice mist produced.

http://www.youtube.com/watch?v=0o6pcfMJNw0

Side view of current rate and operation.

http://www.youtube.com/watch?v=p824IhYwvk8

And here I increase the rate to what the mazzei rate was, back to my current rate, and down to 3-5 bps? Please note the corresponding increase/decrease in mist vs bubbles..

http://www.youtube.com/watch?v=dgKr3OcmOs8

So, back from commercial...lol

I am pretty sure that Tom is indeed only using this method for his 180 but his lighting is different. PAR may be closer than we think
but I think I am higher PAR than he is right now...avg range 75-100 at substrate and close to 190-200 at surface...

You can see why I am always so interested in bubble rates from the posters...

I know that something was off and looks like I was right....

Even though the mazzei provided good mist that was detectable all over, I had two lingering issues:

1. Consistent plant growth and algae issues (albeit small) that could only be c02 related. Carpet plants were the hardest to keep for me but I can see the signs of poor c02 around here and there. Intermittent issues are always a good indication that c02 may be off.
2. Tremendous usage of c02. Filling a 10lb bottle once a month!

For example my new stauro would do well, than not, than okay in MOST areas but not all. Same with HC. Do well and than get algae covered. Do well and melt. You get the idea.

About 10 days ago now I did the following:

1. Installed a vortech mp20
2. Shut off my mazzei leg and directed that flow to the other legs/outlets. Much improved flow as the mazzei requires a lot.
3. Installed the Rio pump as you see above. Don't laugh it is not permanently placed and I am still 'experimenting'
so aesthetics don't matter :) This also adds a nice flow across the center carpet stauro..
4. Lowered the bubble rate SIGNIFICANTLY as per the video. The highest rate in the last video was the mazzei rate. Compare
that to the rate in the first two videos. Can you see a difference?

Since that time I have observed the following:

1. Tremendous growth in the stauro. Size of plants and leaves increased significantly.
2. Better and earlier pearling. Much more consistent with a water change..
3. Reduction in some of the cladorpha that plauges small areas of substrate and wood.
4. Better growth in all anubias which were lagging somewhat.
5. Better overall growth it seems but it also could be plant momentum that Tom speaks of as things HAVE been going well!

I realize that the improvements were due to many items not just the rio mod, but I am just pointing out I guess that you can think that
you have a great setup (mazzei and good pump) and all is working 'optimally', and things could always be better if you are having lingering issues.

I think now that I will soon have one of those 100% algae free tanks with the great growth that folks here have...

I may not be optimal just yet, but so much better I think with just some small simple improvements.

I feel confident that I will be able to lower the rate more but we will see. No fish stress at all and plants are really doing well...
 
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