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Tiny super efficient CO2 reactor

302K views 380 replies 156 participants last post by  jasonvthomas 
#1 · (Edited)
Go to any Petco and buy this tiny internal filter:
http://www.petco.com/product/13796/Hagen-Elite-Mini-Underwater-Filter.aspx

In the box you will find everything needed to make an extremely efficent in-tank Co2 reactor:

1. Discard the tubing that supplies air to the filter and is meant for aeration, you don't need it.
2. Open the filter - as if your intention is to clean the sponge.
3. Remove the sponge from the compartment.
4. Pull and remove the green flow control slider.This leaves a small opening on the side of the filter.
5. Close the filter without the sponge. When doing that put the CO2 tubing in the small opening mentioned above. Basically 1/2" of the CO2 tubing is now inside the filter, right under the intake, and it's held in place by the closed filter.
6. The filter comes with a flow nozzle. Put the sponge removed in step 3 over this nozzle.
7. Attach the flow nozzle to the filter.
8. Peel off the technical info sticker. It's white and attracts the eyes.
9. Done!

Basically you have done two things:
A. Put the CO2 tubing under the intake of the filter.
B. Attached the sponge on the outtake of the filter.

When the filter runs the CO2 bubbles hit the pump impeller and make a very gentle noise. This is your bubble counter. Count the bubbles with your eyes closed if you want. You will have to get about a foot from the reactor though - it's hard to hear if you are more than 2-3 ft. away.

When the bubles hit the impeller they get broken into tinier bubbles. These tiny bubbles then get trapped in the sponge with 60 gph of water flow disolving them almost 100%.

The few fine bubbles that escape the sponge look like a tiny cloud. It consists of bubbles so fine that they have a hard time floating up to the surface. Even the most gentle side flow carries them to the side and around the plant leaves.

Old design of mine but this $10 filter really makes it possible to make an ideal internal CO2 reactor in literally less than 1 minute. The filter is very small (easy to hide), black (doesn't attract the eyes), and has a strainer that makes the suction gentle enough so snails don't get stuck on the intake, die and block it. Virtually zero maintenance.

Maybe someone could post pictures showing how to do everything I described. I haven't picked up a camera in many months but it seems that life still goes on as usual.

--Nikolay
 
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#2 ·
I have this filter in a shrimp tank. I just run the co2 line into where the air intake is supposed to be. It spreads a big cloud of co2. It is not as efficient as what you describe. I will have to try your method with it, though I may keep at least a small portion of the sponge where it is supposed to be so the shrimp don't get impelled.
 
#3 ·
If you put the sponge where I suggest you will see exactly what I described.

Using a sponge to avoid sucking snails or baby shrimp is fine except that it needs to be cleaned on a regular basis. If you are consistent with cleaning the sponge then the CO2 reactor will have no problem. But if you let the sponge get dirty the water flow will decrease and the amount of CO2 being disolved will also decrease. This may not sound like a big deal but it actualy is because fluctuating conditions in a planted tank are the main cause of problems.

--Nikolay
 
#6 ·
lets see the pics!!! sounds sweeeeeet!
 
#10 ·
I'm using this in my 15gal, it's slightly big, but not too obtrusive.

Because it's a small tank I have the flow control turned all the way down, and it's placed only very slightly above the gravel in order to reduce flow more and protect the critters. (I had to rescue my betta after he got his tail sucked in 5 minutes after I put the filter in - he was fine, just kinda confused)

I took a screw driver and stretched out one of the bottom intake vents and then placed the output from the bubble counter in there. It's working very well and the bubbles are super fine.
 
#11 ·
you can use the Hydor Ario's the same way.
they are whisper quiet and never clog unless
you have a sand substrate. the Co2 bubbles
come out much finer than any disc diffuser,
and the low water current generated helps
distribute the Co2 all over your tank. they
come with or without an LED spotlight.

 
#23 ·
you can use the Hydor Ario's the same way.
they are whisper quiet and never clog unless
you have a sand substrate. the CO2 bubbles
come out much finer than any disc diffuser,
and the low water current generated helps
distribute the CO2 all over your tank. they
come with or without an LED spotlight.

Hi Spypet

The Hydor Aroi models look very promising for CO2 mist introduction. If you don't mind, I have a few questions.

What size is your aquarium that it is in?

Which one of the Hydor Ario models did you use? They come in models 1, 2, 3 and 4.

Models: Aquarium Size ... x gph
Ario 1: 3 - 13 gallons ... 5 - 15 gph
Ario 2: 13 - 26 gallons ... 8 - 30 gph
Ario 3: 26 - 40 gallons ... 8 - 50 gph
Ario 4: 40 - 80 gallons ... 20 - 50 gph

Do all of the different Ario models have the same external dimensions of 1-1/4" x 2-3/4" x 3" high?

http://www.hydor.it/inglese/ario.htm
http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+3669+12216&pcatid=12216

Thanks

Left C
 
#12 ·
Finally got around to trying this a week ago today, it works well - although I don't know what the CO2 levels are night and day. I've just started a 60 gallon, low light, sand and peat moss substrate. I was having a problem with hair algae in the 20 that everything moved from, and in the last week all of it has melted, whether or not the added co2 did it or the increased water volume I don'y know. There is a visible difference in the lace fern ( was the only plants before ). All in all not a bad idea. However the audible bubble counter effect is starting to piss me off, I can here it across the room. Tick tick tick tick tick...
 
#13 ·
hey spypet,
have you used the ario system???
 
#18 · (Edited)
I was at my local Petco and they had an Elite Mini (they only had one left too) so I thought I would give it a shot as a co2 reactor after reading about it here. See pics below!

Elite Mini box



The box contains the filter, flow nozzle, and tube with a venturi aerator.


Water flows in from the bottom of the filter and exits from the hole below. The green tab is the flow control slider.


Take the filter apart and remove the filter sponge as well as the green flow control slider.


Place the flow nozzle into the filter sponge.


Put the filter back together. The hole where the flow control slider was is where your co2 tube goes.


Put the filter sponge nozzle on the filter and your co2 tube in the flow control slider hole.


Place the filter in your tank, plug it in, watch the bubbles fly and the plants pearl!


Overall, the reactor works great in my 56 gallon tank. I placed the filter behind some driftwood in my tank so its out of sight. The output from my canister filter is right above it to help push any bubbles that reach the surface around the tank. The first full day it was hooked up my pH dropped from 7.4 to 7 and could've dropped more had I increased the bubble count. I'm impressed with how tiny the bubbles are when they come out of the reactor and my plants have been pearling like crazy. As other posters mentioned earlier, the reactor does make some noise as co2 passes through the filter. For me, the fans on the lights of my tank are much louder than the noise the reactor makes, so I don't hear anything unless I'm right next to the tank. The filter itself cost me about $10 so its great for someone on a budget. Thanks for the great idea!
 
#24 ·
What does the sponge do? Don't you get the fine bubbles just from running the CO2 through the impeller? It is sure hard to beat the price on this!
If you have the sponge on the bubbles will float to the surface pretty much right above the reactor. If you take it off the bubbles fly all over the place. I orginally had the sponge on with the bubbles floating up to the output on my canister filter, but I ended up taking the sponge off and it seems to do a better job with increasing co2 levels.
 
#22 ·
Nice job on the photos...now this is what i was looking for!!! This would work great for DIY also...NiCe~ :)
 
#26 ·
I've got a 200gph power head set up in my 6' tank as a co2 reactor, I have it hooked up to a spray bar at the back of the tank (directly underneath the spray bar from the canister filter) and it sends a fine mist everywhere, I'm very happy with it (as are the plants)
 
#27 ·
I've found that with impeller dispersers simply putting the hose into the intake will result in "bubble explosions," the loud and scattered bubbling that some of you are seeing.
What I did was just below the green flow adjuster I drilled a 7/16" hole (though really, .2" would have been ideal), and then put one of those white, long, and skinny airstones in it with the barb sticking out of the hole. I then connected the airline to the barb. This creates a steady stream of small bubbles that then get broken up silently and into even smaller bubbles by the impeller. No sponge catch necessary, though you can still add that if you want all the co2 to dissolve.
 
#28 ·
I created a c02 reactor as per Niko's instructions with an extra elite mini underwater filter that I had laying around. I tested it in my 10 gallon signature tank. Drop checker is showing a constant lime green color even when with small airstone running and excessive surface agitation via the 200 Hagen HOB filter that I am using. The drop checker solution is 4dkh and I have changed the solution several times to eliminate solution error and I get blue turning to lime green withing hours each and everytime.. To me, this would suggest that such a c02 reactor is pretty darn efficient. If you are going to try this in a 10 gallon, you may want to run a small airstone, just to be safe.
 
#29 ·
Ah thank you, AquaHokie, for the pictures! They really show how pathetically simple this project is! For the price and simplicity of set-up this reactor is the rock bottom itself.

Adding an air stone at the end of the CO2 tubing is "an improvement" of the design because it reduces or eliminates the noise completely. Instead of an air stone you could add a 1/4 inch long piece of chopstick at the end of the CO2 tubing. The result is the same - finer bubbles and less or no noise.

The sponge traps the CO2 bubbles and the water rushing through the channels in the sponge disolves the trapped bubbles very well. A bigger sponge will result in almost 100% efficiency. If the pump outflow ponts down the efficiency is also improved. If you care - look for an older post of mine with pictures of another version of the same reactor. Either way the combination of a CO2 tubing + powerhead + sponge is very simple and very efficient.

If you remove the sponge and let CO2 bubbles float all over the tank you will sacrifice a lot of the water clarity. Each tiny bubble reflects the light and makes the water appear more or less milky when the tank is viewed from a distance. If you don't care about the looks then at least do something that seems to help both the plants and the appearance - direct the flow along the tank length and closer to the bottom. This way the bubbles that float up will be trapped under the plant leaves. This seems to boost the plant metabolism (direct contact of the leaves with CO2 bubbles) and also keeps most of the bubbles out of sight so you get better water clarity.

I don't remember if I mentioned before - mount the black internal filter in such a way that if the electricity stops the CO2 bubbles escape out of the filter chamber. If you let the gas accumulate around the impeller during the power failure the filter may not prime - the impeller may spin in CO2 instead of water, haha.

Ok, too much talk about such a simple project, I think everyone got the idea, especially with those detailed pictures. Thank you again, AquaHokuie!

--Nikolay
 
#30 ·
I love this reactor. I find that with a quart of sugar-yeast there's a saturation of CO2 in a 10 gallon tank and the outflow sponge doesn't have any appreciable effect on it except to diffuse the flow of water (which is too much in a 10 gallon betta tank otherwise). I'm planning on getting a 1.5G hex that takes a 10W compact fluorescent and matching it up with this as a filter and CO2 diffuser to see what sort of cute nano tank I can come up with.

I mounted mine sideways so that if the power does go out the air accumulates and exits the side intake vents.

At $10 its actually a dollar cheaper than the air powered cartridge filter that my GF has been using, and since I don't care about carbon filtration and highly value sponges...
 
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