CO2 diffuser for cheap!!

Tom Barr

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I recently tested some fine pore Sweetwater diffusers for CO2 dosing.
These produced better consistency in terms of bubble size and smaller bubbles than the Azoo/Ehiem and other disc type of diffusers(both were new for the comparison, time will see how both behave, but the consistecy is better at this point). They also have more gas volume per unit than disc do as well and there is little to no back pressure.

One idea was to place on the smaller air stones inside the return line coming into the tank from a canister filter. This is very simple and they are about 1/2" square on a side at the smallest.

I've used the Rena air stones in the past, they are decent but these seem to produce better bubbles size consistency. They 1.70$ for the smaller ones and the larger up to 4.23$ from www.aquaticeco.

http://www.aquaticeco.com/index.cfm/fuseaction/product.detail/iid/9751/cid/2328

The small ones are all we need in most cases.
Plus Aqeco has dang near everything.
The small one is as good if not better than the best Azoo disc.

The goal is to reduce backpressure and maintain flow, venturi valves like Kent's 1/2" model constrict flow too much(flow rates of 180-1800gph). By making a larger(say 2-3") tube section to place a mist stones or a powerhead driven venturi, the mist can be added.

You can make your own venturi inlet fairly easily also. Take a smaller input line(say1/2") and connecting it to larger out line(say 3/4") and adding the gas inlet right after where the different sizes meet will mimic a venturi(there is a pressure differential between the different tubing sizes and that is what causes the venturi) Simply using a piece if rigid air line tubing and melt the tip some to reduce the orifice size and adjust into place.

I've does this with air in the past, but not CO2, but should work the same.
It is also simpler than the atomizer idea with the 2-3" tubing etc.

I have hooked up the Ultra fine mist duiffusers from Aquatic Eco and these are very very well built and far superior to anything I've ever seen as far as a disc(ADA, any brand you can think of or can find). You'll never wear these out or break them. The space for producing the mist is much larger than any disc sold today and and the pores are much finer(hence the nmeed for backpressure..
http://www.aquaticeco.com/index.cfm/fuseaction/product.detail/iid/9775/cid/2339

This produces very small and very consistent.100-500micron bubble size.
The largest bubbles from these are the smallest from a disc.

At 55$, these are serious misting units. I use Tygon tubing since the backpressure is higher(25psi). To clean them, bleach can be used, but most just take them out and give the stone a light sanding, back it goes.

If you have a 100+ gal tank(up to a 500gal tank or so) and a good source of current, these will supply the mist very well. Better than any other stone/disc. Cost less than an AM 1000 reactor also. Or go with 2-3 of the sweetwater diffuser stones.

I cannot say how impressed I am at the quality and ablilty of these ultra fine bubble plates as well as the Sweetwater diffuser stones. Better than the Azoo and the other disc I've tried out.
The Sweetwater stones are about the same cost as limewood, but appear to produce better bubble sizing. We will see how well they hold up over time. So far though, they seem easier to use, less backpressure, 10X or more cheaper.

They are only 1.70$ea after all.

Regards,
Tom Barr

www.BarrReport.com
 

Kharn

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Jan 24, 2005
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Re: CO2 diffuser for cheap!!

Hi

I have bought 2 of the Plate diffusers that im gonna put in my tank.

Do you use a bubble counter or just crank the needle valve open for the Plate Diffusers ?

Best regards Jimmy from Sweden.

PS. i agree about the quality absolutely stunning :)
 

Tom Barr

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Re: CO2 diffuser for cheap!!

They are good, but also realize tyou need higher pressure to run them, so good tubing, proper adaptors(they are for 1/4" tubing), and Tygon tyubing is totally worth the extra $ if you go this route.

For the $, the sweetwater stones are extremely hard to beat.

Regards,
Tom Barr
 

Cornhusker

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Jan 23, 2005
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Re: CO2 diffuser for cheap!!

tom,now your talking my langauge. CHEAP! would these work useing regular 3/16 tubing and running them in a sequence of mabey 4 hooked together? if that would work what would be exact part# at that website so a guy gets the right ones.would 20psi be enough to operate that many? regards,cornhusker :) :)
 

reiverix

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Re: CO2 diffuser for cheap!!

That's a nice website. I've never heard of them before. I may order a few of the diffusers if I find some other stuff that catches my eye.
 

Jersey Scape

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Re: CO2 diffuser for cheap!!

not to hijack the thread but a quick question while we are on the topic of Co2. If I have a 15 gallon with pressurized Co2 delivery, what should my "bubbles per second" be? I am running at about 2....is that too much ?

thanks
 

Tom Barr

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Re: CO2 diffuser for cheap!!

At very high light, I aqdd about 1 bubble every 3 seconds to a 20 gal.
I add about 6 bubbles(they are 3x larger) to 350gal per second.

Mist or Reactor methods.

Regards,
Tom Barr
 

Tom Wood

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Jan 24, 2005
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Re: CO2 diffuser for cheap!!

The site says the diffuser stones are for ozone, whereas the plates are for CO2. I've melted the regular blue ceramic airstones with CO2, do you know for certain that the cheaper Sweetwater stones will work with CO2? I'll be placing it in the intake pipe of my external pump, and a chunk of stone coming off would be bad. :eek:

TW
 

Tom Barr

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Re: CO2 diffuser for cheap!!

They work well with CO2, I've seen no decline, Sweetwater are pretty good products, we used their air blowers in large scale operations.

If something can handle the corrosive nature of O3, they can handle the CO2(mild acid).

The plates are for large tanks.
They also need 25psi, so the tubing and connections need to be very good, leaks, and blowing off of the lines can occur much more at 25psi than our typical 1-2psi, or 10-15psi for some disc.

I get the same sized bubbles mist from the SW as I do from the 10psi disc.

Regards,
Tom Barr
 

PMC

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Oct 24, 2005
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Re: CO2 diffuser for cheap!!

Tom, You said in the first part of this thread that

"One idea was to place on the smaller air stones inside the return line coming into the tank from a canister filter. This is very simple and they are about 1/2" square on a side at the smallest."

I'm wondering how I can do this with my Eheim 2213 with it's 1/2" piping. I could go out to my local hardware store and get some 3/4" or 1" PVC and construct a spraybar, place it vertically in the tank with the airstone at the bottom. Is this what you mean? And would this be better than, say just putting the airstone at the bottom of the tank with the vertical spraybar above it?

Thanks,

Peter
 

Detritus Mulm

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Jun 12, 2005
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Re: CO2 diffuser for cheap!!

You could use something like this (5463K561) from McmasterCarr. You would just splice the TEE into you return hose and put the stone in the threaded hole sealed of with an end cap. Of course you would need some Teflon tape and Silicone caulk to make your CO2/Cap connections leak free.
 

PK1

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Oct 7, 2005
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Re: CO2 diffuser for cheap!!

Do you get a true "mist" coming out of the spray bar with this method? I like the idea because this could replace my external (homemade) reactor that has too much pressure drop in it and therefore reduces flow on my 2217 eheim... but wouldn't the fine bubbles coalesce in the tubing and come out as much fewer larger bubbles that would simply float to the surface and dissipate into the air?
 

Detritus Mulm

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Jun 12, 2005
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Re: CO2 diffuser for cheap!!

Sorry if I misled you, i'm not using mist yet, but seriously considering it. I just thought the plumbing idea might work for you.

I use a Powerhead to create my bubbles and blow them under the UG plate (RUGF). I'm currently at 25 PPM and hoping to get to 30, but I think this will be the limit of this method.
 

Tom Wood

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Re: CO2 diffuser for cheap!!

I added one of the Sweetwater small stones to my tank yesterday. Very nice bubble size. I had intended to put it in the return line to my external circulation pump, but I've never liked all the bubbles it makes in the water. So I placed the stone next to the wall of my overflow and just let the bubbles rise up and then get swept over into the in-tank sump. Works well, but is obviously not maximum efficiency.

I bought five since they have a $5 'order charge' plus about $4 shipping.

Man oh man I am so happy to see real plant growth again after solving the magnesium mystery. :p

TW
 

Tom Barr

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Re: CO2 diffuser for cheap!!

Well, now with two things going for you, things should do much better.
Tap water reports of Mg vary, Ca, to a lesser degree from everything I've heard.

Those SW stones are nice.
Best stone for the $.


Regards,
Tom Barr
 

Tom Wood

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Re: CO2 diffuser for cheap!!

Just FYI, I moved the stone to the intake on my external pump, and left it there for a day to measure the difference in additional CO2, if any. (Not much) When I pulled it out to put it back in the tank, I noticed that the 'upstream' end was dark green because it had picked up a lot of gunk in the stream. When I put it back in the tank, the bubble stream was irregular with a lot of bigger bubbles. So I replaced it with another one. I'm thinking that they wouldn't do well long term in the inflow of a pump unless that water was already well filtered.

TW
 

reiverix

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Re: CO2 diffuser for cheap!!

Sweetwater 1.5" diffuser, fine pore. Item AS10 from Aquatic Eco-Systems, Inc.

sweetwaterpic.JPG
 

Tom Barr

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Re: CO2 diffuser for cheap!!

I also tested the "Red Sea CO2 200" reactor disc duffuser.
Ran 15-20$ frommost outlets, pretty nice and has the bubbe counter in there and has a nice inlet for CO2 line connection.

Regards,
Tom Barr
 

Cornhusker

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Jan 23, 2005
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Re: CO2 diffuser for cheap!!

tom, i'm testing a small diy bubble counter to use with the sweetwater stone . CHEAP! i'll share results coming up. regards,cornhusker :) :)