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Needle wheel pump

28K views 66 replies 20 participants last post by  jart 
#1 ·
I was reading a thread and thought what the heck is this? I must have missed the boat when this topic came up. Anyone care to explain what this is and why it so much better then ceramic diffusor in the water flow. From what I gather you run the pump externally into the return of your canister and bubble the CO2 into the pump?
 
#2 ·
The pumps are used mainly for protein skimmers. But for our application it works very well and has a few added benefits.

One would be you get added flow to the tank.
2nd. You get tons of fine mist distributed in the tank much like a Mazzei or diffuser.

The impeller is a little different than your average impeller. Its needle like instead of paddle like. This is what provides the fine mist. :)

I hope that all made sense..
http://www.plantedtank.net/forums/e...eel-co2-diffusion-fractionating-impeller.html

-Orlando

P.S

You dont have to plumb them into filter lines. I use them on there own separate loops...
 
#4 ·
I've been using them for a while, and think they are great.
extremely efficient, and easier to dial in than mazzei. (my opinion)
the only downside, which I consider an upside is the microbubbles.

microbubbles of CO2 enter the water column and are spread all around the tank.
some say they are unsightly, I say they help me visually manage flow.
If I see microbubbles entering and leaving the plantbeds, then I know flow is good.
this has been extremely beneficial to me when managing dense plantings.

a couple feet back from the tank you cannot see the bubbles.
for closeup photos you can shut off the gas.
 
#8 ·
I'm a little confused about what you are trying to do? It seems that you are trying to make carbonated water!

What is controlling the final concentration of CO2 in your set up? Tom Barr recommends 30 ppm and I think 20 ppm is more than enough. What are you setting as your tank limit?

At 20 ppm I more than double the biomass of my plants in 6 mo.
 
#6 ·
Adding a pump to the return of a canister significantly boosts the canister output. Running a closed loop will increase water movement in the tank even further.

The main benefits over a ceramic disk are bubble size and lack of cleaning. Some people claim to have ceramic diffusers that produce ultrafine, mist like bubbles, but I have yet to see one. A plumbed needlewheel produces extremely small bubbles.
Ceramic diffusers do best with regular cleaning, if needlewheel pumps ever need to be cleaned at all, it is very infrequent.

Overall, it is just another way of getting CO2 into the tank. If you already have adequate water movement, and a well functioning ceramic disc that you don't mind cleaning, then there really is no benefit.
 
#9 ·
In my case there is no target or controller and I have only a needle valve to meter the gas after the regulator, but the needlewheel pump could be part of any controlled system that kicks gas on and off by a pH reading or something else. and it is a lot like carbonated water ;) or more like a nice stout :drinkers: .

the bubbles are *tiny* when its going well, think of the little bubbles in guinness. After a pint is pulled notice the bubbles move downwards, swirl around - they follow flow readily and are less in a hurry to reach the surface. So CO2 is distributed all around the tank as a fine mist. I have no scientific reason why I've had so much success using needlewheels, but I like it very much.
 
#13 ·
I remember seeing wasserpest's suggestion to put an AC30 powerhead ontop of a sponge, running CO2 into the impeller. That was around '06, and I remember seeing people melting holes in the impeller blades and also cutting them to increase fractioning not too long after that. I cant remember where I saw the OTP series needlewheels in action, maybe the youtube video. But I got one ASAP and now I have 3 running. I use smaller powerheads on smaller tanks, some with modified impellers.

one thing I haven't tried yet is stainless mesh for chopping up the bubbles. How about you Orlando? I'm a bit worried about it becoming clogged with debris but maybe thats not an issue. I have a stock OTP-1000 that has run 24/7 for 1.5 years now and hasn't been cleaned yet. I don't prefilter the intake on it. So for a long term solution I think the needlewheel misting is pretty stable.
 
#14 ·
That youtube video is what got me started! Lol!

I have seen people use those mesh mods, have you seen them? It a little kit with some funky mesh and I think zip ties?
I know the reef folks use them all the time. Personally I dont really see a need for them with our tanks.
One thing I was thinking of is building a PVC fitting with one of Hydor ceramic tubes inside afixed some how and have co2 mist going into the pump.
What do you think?
 
#18 · (Edited)
I found this thread on RC that is specific to my octopus pumps, looks like the impeller mod is reversible since the mesh is just zip tied to the blades and trimmed. Let me know how it goes. I think I'll order some of the enkamat mesh this week.

glad this thread got started..just a little nudge to get me to go a bit further with the needlewheel method.
I monitor power draw on my pumps so I'll be able to see what happens there also.

edit : well I read the thread(s) closer instead of just a skim, and its not reversible (doh!)
you cut off the top row of impeller blades. I do have a spare impeller but I still hope I dont screw up when I add the mesh.
 
#23 ·
I had a discussion with Adam a few weeks back regarding needle wheel pumps and decided to give it a shot at co2 misting myself. I order two octopus 1000 needle wheels from Jen's Saltwater Haven for $45 (they were the cheapest I found online) ea and they finally arrived last Friday after a looooong wait.

I also had the impellers modified with two layers of enkamat I bought last week on eBay ($6 for a 6x6") and I was astonished by the results.

Here is the modified impeller:


http://img.photobucket.com/albums/v351/dumaaa/IMG_8266.jpg
http://img.photobucket.com/albums/v351/dumaaa/IMG_8267.jpg

I didn't want to damage it so I decided not to remove the top layer of the impeller. However, I did tighten the mesh to prevent it from rubbing.

The pump was very efficient as the bubbles were microscopic and remained in suspension for a while before reaching to the surface. Minutes after operation, fishes started to grasp for air near the surface of the tank and I had to reduce the number of bubbles per second from the original output.

As mentioned by Adam, the mist could also serve as a very good flow indicator. Most of the areas in my 55 gallon tank is virtually filled with co2 bubbles. Just by looking at the movement of the bubbles, I could tell where the turbulence is the strongest and where the water stagnates.

I am normally a forum lurker and I am always too lazy to post anything in threads. But I wanted to spread the word a bit and encourage others to try this method.
 
#24 ·
thanks for sharing your experience! I should have my mesh soon and I'll also try to add it without snipping back the impeller blades. Do you notice any additional heat from the pump ( or ideally do you have a killawatt to monitor power usage ) ? too bad on the high price - I got my OTP-1000 pumps for around $26 each, but I do agree that it isnt possible to find it for that price now. :( Either way they seem to be very durable pumps and should last for a long time.
 
#27 · (Edited)
I am extremely pleased with the results. I wouldn't mind putting out a few extra dollars and I take it that the benefits would ultimately outweigh the costs in the long run.

I did notice that the pump ran a bit warmer than the average pump. I presume this is from normal operation? Or would the mesh put a strain on the pump because of the added weight and restriction?
 
#25 ·
I realize that there are many different paths that can be taken in order to get to the same destination, but I am having a very difficult time understanding why should I choose to take this one.

I currently use an Aqua Medic CO2 Reactor 1000, hanging externally on the back of the tank, with the return water from a Fluval 403 canister filter flowing through it (the return hose is actually set up with a "T", where one half goes through the reactor, and the other half goes to a Loc-Line flexible return, with each side having it's own ball valve so I can adjust the flow; currently, just about all of the return water is going to the reactor). The CO2 is very efficiently dissolved into the water, with no bubbles escaping out into the tank, where it seems to me they would just rise to the surface and pop, which would allow the CO2 to escape.

I have seen where other aquarists also use some type of reactor, but have also seen the various methods of blowing a CO2 mist out into the tank. It seems to me that the reactor method would be more efficient and a lot less likely to waste the CO2. Plus, I doubt any of the fish in nature would be presented with a cloud of CO2 in their water. Is there any real benefit from using this needle wheel pump method over a reactor?

Thanks,

Andy
 
#26 ·
There is a real benefit indeed. If you read looking4roselines post they are mentioned in there.

Benefits..

1) No loss of flow like you would with a reactor.

2) You actually will benefit from the added flow by using the fine mist as a flow pattern indicator. This will help eliminate dead spots.

3) Lower Bubble counts on your regulator saving you co2.

4) I have long preferred misting over anything else, but this is just my opinion.

The only draw back that I can see is that it is one more thing you have to plug in:(


Regards,
Orlando
 
#28 ·
on top of what Orlando added to Andy's question - there is the issue of mist vs dissolved in the water.
I cannot explain why it seems to work better, but when I first switched from reactors to mist I was impressed at the performance with lower bubble rates. So less gas used and better growth. Is it the added flow? the tiny bubbles touching the plants? dunno. Your results may vary ;)

looking4roselines said:
I did notice that the pump ran a bit warmer than the average pump. I presume this is from normal operation? Or would the mesh put a strain on the pump because of the added weight and restriction?
thats one of my concerns. I'll monitor power usage before and after meshmod and see if the difference is significant.
 
#30 ·
There is a way to test these modifications. Use a killawatt to test the pump use before and after the mod. The wattage should decrease as the air/co2 intake is increased. More air/co2=Less resistance=less wattage. I am modding my skimmers on my reefs and read this on several sites but didn't bookmark any. Just search" skimmer mesh mod" and at least a couple of those forums will have it. I intend to add mesh to the top of one of my needlewheels and see if it drags and what results i get on the killawatt. If it drags I assume wattage will go up even though you would see a performance increase. This could also cause a heat increase. I will probably end up pulling the needlewheels apart but we will see. Maybe ill do the impeller in my 3 gal plant tank, but i doubt it.
 
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