# DIY diffuser for DIY C02



## iadubber (Jan 23, 2012)

I have had great luck with some cotton ball shoved in the end of a piece of silicone tubing. It's the smallest bubbles I've seen from a DIY setup.


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## Izzy- (Jun 11, 2014)

iadubber said:


> I have had great luck with some cotton ball shoved in the end of a piece of silicone tubing. It's the smallest bubbles I've seen from a DIY setup.


I never have success with DIY diffusers lol I'll try this.


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## burr740 (Feb 19, 2014)

Aquaclear HOB's make a great diffuser due to their unique design. Stuff a piece of cotton ball or chopstick into the co2 line as a pre-diffuser, then run it straight into the AQs intake pipe. Here's mine on a 20H. 











I used to have just the raw, open line going in there. That was pretty good, but you could hear a distinct "chirp" every time a bubble hit the prop. And there were a few bubbles that made it out into the water. Once I started pre-diffusing it, zero bubbles, and the only noise is a very low sizzle that is barely noticeable.


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## mcubed45 (Jun 30, 2010)

Just use a regular glass diffuser. They work fine with DIY. The only reason it won't work is if you have leaks.


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## Solcielo lawrencia (Dec 30, 2013)

Bamboo chopstick stuck into the end of the tubing.


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## mcasper (Sep 19, 2014)

Oh man, bye bye diffusion ladder! I think that I'm going to go the route of tying the C02 output into the intake of my Hagan HOB. I've heard that this could potentially shorten the life of my filter motor... but I should probably have a filter with a greater flow rate anyway, so if it breaks I'll have an excuse to buy a bigger one. 

On a side note, just for sh!ts I stuffed some cotton into the C02 output of my diffusion ladder last night. I have to say that this worked surprisingly well. The bubbles produced were much smaller. Though it wasn't particularly compatible with the ladder because the small bubbles didn't have enough buoyant force to navigate the bubble track. They would stack up on the first rung and coalesce into bubbles large enough to shoot up the track, so the effect was minimal.


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## jmf3460 (Aug 21, 2013)

this is weird but a cigarette filter works great! literally the best diy co2 diffuser ive ever used and I have tried them all


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## msebar (Mar 13, 2014)

jmf3460 said:


> this is weird but a cigarette filter works great! literally the best diy co2 diffuser ive ever used and I have tried them all


And how do you hook this up????


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## jmf3460 (Aug 21, 2013)

you just remove the filter from the cigarette and stuff it in the end of the airline tubing, watch these youtube videos on it here...what I did was put the bubbles directly under the intake of one of my hob filters and then it dispersed it even more.
https://www.youtube.com/results?search_query=cigarette+filter+as+co2+diffuser


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## TankFreak420 (May 31, 2014)

My favorite defuser so far is a power head. Expensive I know but by far the best if you have one kicking around. The only diy type defuser I have had luck with is a bell type (I think thats what its called). Basically I took a plastic water bottle, drilled a hole in the cap for a air line, drilled 2 holes on the side for suction cups, and cut the bottom off. Put the clear bottle in my tank under my HOB filter and hooked the air line up to my DIY co2. The bottle fills with co2 and about every 30min or so it would release a big bubble, but it had a really long saturation time. It worked much better than a air stone, or bamboo sticks ( acording to my plants anyway). I have seen people do something similar with old gravel vacuums. I am going to have to try the cigarette filter now!


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## TankFreak420 (May 31, 2014)

Went to the smoke shop yesterday and bought "Top premium filters", it was $2.17 for 100 tips. Got home and tossed some air line tubing in the oven as the lowest heat setting untell the oven was preheated. Pulled a peace out and put one end over the syringe I use to dose ferts (just to open the air line up some more). Then I just held onto the other end while letting the weight of the syringe pull the line straight wile it cooled for a few min. Then pulled the syringe off, rolled a filter smaller, and jammed it in the line. Waited a few hours and found out my bubble counter was leaking, fixed it and let it sit over night. Hooked it back up this morning and I think I found my new favorite defuser.


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## nawilson89 (Nov 17, 2014)

burr740 said:


> Aquaclear HOB's make a great diffuser due to their unique design. Stuff a piece of cotton ball or chopstick into the co2 line as a pre-diffuser, then run it straight into the AQs intake pipe. Here's mine on a 20H.
> 
> 
> 
> ...


I'm going to be trying this out in a few days. Just so I have it correct, your CO2 is stuck into the intake of the HOB filter?


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## burr740 (Feb 19, 2014)

nawilson89 said:


> I'm going to be trying this out in a few days. Just so I have it correct, your CO2 is stuck into the intake of the HOB filter?


Correct. But it has to be an Aquaclear filter. Other HOBs dont work well due to how the water passes through the media. CO2 will off-gas in the chamber behind the filter pads before it has a chance to dissolve.


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## nawilson89 (Nov 17, 2014)

burr740 said:


> Correct. But it has to be an Aquaclear filter. Other HOBs dont work well due to how the water passes through the media. CO2 will off-gas in the chamber behind the filter pads before it has a chance to dissolve.


Darn. Mine is API. So then it makes me think, how would i get the CO2 into the tank? I was just going to run my tube straight into the tank. I never purchased a diffuser.


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## burr740 (Feb 19, 2014)

nawilson89 said:


> Darn. Mine is API. So then it makes me think, how would i get the CO2 into the tank? I was just going to run my tube straight into the tank. I never purchased a diffuser.


I would try all of the following and see which one produced the smallest bubbles - a piece of chopstick, a cigarette filter, or a tight wad of regular cotton ball stuffed into the line. Then place it low in the tank, under the filter outflow so the current will further disperse the mist bubbles into the water. You want the bubbles to remain in the water as long as possible before reaching the surface.

If your tank is big enough for a powerhead you can use that. Run the line straight into the intake, again pre-diffused with a piece of cotton ball or chopstick. Before I got a reactor that's what I did in my 75 gal with pretty good results.


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## mcasper (Sep 19, 2014)

nawilson89 said:


> I'm going to be trying this out in a few days. Just so I have it correct, your CO2 is stuck into the intake of the HOB filter?


This is the route that I ended up taking. It works great for my 20gal tall and is much easier to maintain compared the diffusion ladder. My plants seem happy and healthy.


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## Josh40996 (Aug 1, 2011)

The method I use has 100% dissolution of CO2 into the aquarium, it is relatively easy to make but can be quite bulky in sub 15 gallon tanks. The idea is to attach a water pump to a long tube and bubble in CO2 from the bottom, the buoyancy of the CO2 is great enough to keep it trapped in the tube but the water pump keeps fast moving water moving past the bubble, dissolving the CO2 into the water with 100% of the CO2 dissolved in the water. 


The tube could be that from a gravel cleaner or PVC pipe if you are not too bothered about seeing the reactor in action.


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## ErtyJr (Jun 21, 2014)

I think it's worth mentioning that a good and simple diffuser is also a wooden air stone. Works just as well or better then a chopstick, but won't break down like a normal air stone would, and bubbles are much smaller.
http://www.amazon.com/gp/aw/d/B0002APUP8?qid=1419995861&sr=8-1&vs=1


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## jrill (Nov 20, 2013)

http://www.aquaticquotient.com/forum/showthread.php/13643-Tom-Barr-s-DIY-Internal-Reactor-w-venturi


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## hplowe (Oct 28, 2014)

May I ask a dumb question? Why run this into the intake of a HOB, does this not cause you to lose most of the CO2 in the waterfall portion of the filter? it is exposed to air alot.


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## Viper (Jan 9, 2013)

burr740 said:


> Aquaclear HOB's make a great diffuser due to their unique design. Stuff a piece of cotton ball or chopstick into the co2 line as a pre-diffuser, then run it straight into the AQs intake pipe. Here's mine on a 20H.
> 
> 
> 
> ...


I know I'm late to the party on this thread, but I took this advice as my glass diffuser just wasn't cutting it. I put some wadded up cotton ball in there and then drilled a hole on the intake of my AC filter. With my glass diffuser and at this bubble rate (~2 bps), my drop checker would be a blue/green color (mostly blue). With this new method, at this bubble rate, my drop checker was nearly all green. Thanks for the idea!

Side question, will the cotton ball get all jammed up like the glass diffuser did or will the Co2 actually break it down and it need to be replaced after a while?


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