# air stone or glass diffuser?



## DVS Moss (Jun 1, 2009)

maybe a silly question, but i have to ask after reading the sticky and getting all excited for the second time.

would a glass diffuser work better with DIY Co2 then one those '' thumb sized '' air stones?


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## cell (Mar 9, 2009)

The glass diffuser is better because it makes smaller bubbles. However it needs a lot of pressure to force co2 out. 

I have a ladder kind of diffuser. It works. Plus, the top part of the ladder acts as a CO2 bell. CO2 tubing was provided as well! With it, I recommend also using DIY Jelly-CO2 recipe.


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## DVS Moss (Jun 1, 2009)

cell said:


> The glass diffuser is better because it makes smaller bubbles. However it needs a lot of pressure to force co2 out.
> 
> I have a ladder kind of diffuser. It works. Plus, the top part of the ladder acts as a CO2 bell. CO2 tubing was provided as well! With it, I recommend also using DIY Jelly-CO2 recipe.


would a glass diffuser work in a DIY CO2 system like the one suggested in the stickies?

or should i just use an air stone?


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## Shad0w (Nov 13, 2006)

glass diffuser have fine holes, take lot of CO2 pressure. With DIY CO2, it make take a while before it has the pressure to push CO2 through.


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## DVS Moss (Jun 1, 2009)

Shad0w said:


> glass diffuser have fine holes, take lot of CO2 pressure. With DIY CO2, it make take a while before it has the pressure to push CO2 through.


are u saying it wont work good or that it will work but may take some time?

would a small air stone be better?


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## Philosophos (Mar 1, 2009)

Go with the air stone. Issues with diffusers on DIY are pretty much infamous because of the pressure issues. For the price of a mid-range diffuser, you could do a needlewheel with a cheap submersible pump, then use a timer to control the on/off for the pump. Kinda works like a DIY solenoid because when it's off, the bubbles directly from the CO2 line are too large to diffuse effectively.

-Philosophos


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## WhiteDevil (May 7, 2009)

get a ceramic air stone.

I had regular air stones they crumble with CO2, I got a glass diffuser that pressurized air cant even get through. I recommend a ceramic stone. a 2" ceramic by me is $3.99


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## cbwmn (Dec 18, 2007)

DVS Moss said:


> maybe a silly question, but i have to ask after reading the sticky and getting all excited for the second time.
> 
> would a glass diffuser work better with DIY Co2 then one those '' thumb sized '' air stones?


DVS
I have two tanks w/DIY CO2 and a 46 gallon w/pressurized CO2.
I use a hard plastic tube and inject the CO2 directly into the filter intake.
It works great on the 46 which has an XP2 canister filter.
On the other tanks, I have HOB filters which cause more water 
turbulence and a lot of the CO2 is gassed off.
Everything being considered, I believe your best bet would be to inject 
through your filter intake. 
On the HOB filters, you do hear a "spitting" sound from the CO2 being injected.
With the XP2 it is completely silent.

With DIY, I had NO success with air stones or ceramic diffusers. 
They both required a lot of pressure build up which caused leaks in the system.
The CO2 ladder does work also, but not as well as injecting through a filter.

Good luck
Charles


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## DVS Moss (Jun 1, 2009)

cbwmn said:


> DVS
> I have two tanks w/DIY CO2 and a 46 gallon w/pressurized CO2.
> I use a hard plastic tube and inject the CO2 directly into the filter intake.
> It works great on the 46 which has an XP2 canister filter.
> ...


how would i incorporate ur method with an Aqua clear 20?

thanks


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## Philosophos (Mar 1, 2009)

Getting good distribution with an AQ 20 through this method seems like a pain. CO2 rises, and those trickle filters just lay the new water right out at the top gently. I picked up a RIO 180 for $12 and pulled a needle wheel mod in less than an hour; distribution beats anything I've used.

-Philosophos


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## bosmahe1 (May 14, 2005)

Philsophos,

Can you tell me how the RIO 180 mod compares to an external PVC reactor attached to output of canister filter?


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## Philosophos (Mar 1, 2009)

I've never liked external reactors. They're expensive, and DIY is as much as you'd pay for disc or needle wheel. On top of all that, they reduce flow rate.

Complete diffusion isn't as good as leaving visible micro bubbles, either. While I don't like argumentum ad verecundium, both Takashi Amano and Tom Barr show this preference in their methods. I consider this a very good endorsement, given their somewhat differing approaches. The reasoning behind it is something to do with breaking the barrier of dead water close to the plant leaf. 

If you look around you can find a couple tests showing a good diffuser will work as well or better than a reactor for diffusing when the distribution is good, but distribution has always been an issue.

In any case, it's not just the rio180 that can be used, but it's certainly cheap and appropriate for small tanks. The varied flow direction and increased flow rate has done great things for clearing out detritus on my tank. My drop checker (4dkh solution) with a diffuser was perhaps dark olive green at this time of day, about an hour and a half after CO2 kicking on. Now it's nearly yellow, and I haven't touched the needle valve. 

Basically you end up with diffusion and distribution, as well as higher efficiency. The worst of it is that it's a bit of a pain trying to find a place where it looks good, creates proper distribution, and won't blow your plants over.

-Philosophos


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## cell (Mar 9, 2009)

DVS Moss said:


> how would i incorporate ur method with an Aqua clear 20?
> 
> thanks


I did it in a 10 gallon with an aquaclear 150 filter. I could see my plants making bubbles so I suppose it works. Also, because of the water movement that the filter makes, I suppose CO2 levels can't reach a deadly level.


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## Scotty (Jun 11, 2009)

When I was doing DIY CO2, I used an air stone to no avail. Like someone said earlier they just crumble. Well here is my suggestion, Go to your local Asian restaurant a pick up a few chopsticks. Cut them to a length of about 1 inch. Then stick one end in a pencil sharpener to taper the it. Stick the tapered end in the tubing. Mount the chop stick in front of a powerhead to blow the tiny bubbles around. And voila, free diffuser. Does not take a lot of pressure to work. Works really well.

That is my advice....Try it!!   

Scott


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## bosmahe1 (May 14, 2005)

Good excuse to get General Tao's chicken today.


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## bosmahe1 (May 14, 2005)

I went from an inline PVC Reactor (connected to XP2 output) that I had been using for over a year, to just putting the co2 into the Rena input line. I kept the bps rate the same for a few days but my drop checker turned a little bluer. Increasing the bps fixed this but every now and then I would get a huge flood of bubbles before settling down to the usual flow of bubbles. I guess this is what was described as a "burp" when a huge bubble of trapped co2 gets sucked up by the impeller. I did like the increased water flow with the Reactor removed. I am currently using a Rio 180 as a diffuser. It works well, very efficient, I actually was able to reduce the bps rate to below that used with the PVC Reactor and stay a nice light lime green. The bubbles are extremely small, almost looking like dust blowing around. What I don't like about it is, there is now another piece of hardware in the tank and it has an annoying spitting sound when a bubble hits the impeller. This may be the most efficient diffuser I've used so far but the trade off is, it's noisy and ugly. I'll keep using the Rio though, until there is a new idea to try.


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## hiddenleaf (Mar 26, 2009)

i did the chopstick thing before, and it works too. I currently using Redsea wooden airstone now, its pretty good, I let it sit down under the outflow from canister filter and the water push the bubbles around the tank right before it reach the top.


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## Philosophos (Mar 1, 2009)

Did you clip the fins on the impeller, to create a needle wheel/fractioning impeller? If not, you might be getting bigger bubbles for a reason. I get little spurts, but nothing I'd call a belch of gas.

-Philosophos


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## bosmahe1 (May 14, 2005)

The belching I described was when I was injecting co2 into the input of my XP2 filter. I did make an attempt to do the needlewheel mod on the Rio 180 but the blades were to brittle so it just split off of the impeller. Maybe they are using a harder plastic now. Anyway, I cut all of the blades to make them even, so they are narrower than stock now. It pushes less water now but that is good for me the way I have the bubbles shooting into the stream coming from the XP2. The bubbles can be described as a mist so small that it looks like dust blowing everywhere. Its very efficient but a little noisey, the tank looks like 7 UP also. I don't particularly like that look but it sure does grow plants. 

I'm going to try the scotch brite pad mod to see if that will make it more quiet.


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## Philosophos (Mar 1, 2009)

Ya, the mist isn't pretty, but it sure works.

What did you use to cut the impeller? I did my mod only about 2-3 months ago, and a hobby knife worked just fine.

I've got a smaller submersible pump sitting around that was originally planned for the mod; I might test the pad method my self.

-Philosophos


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## bosmahe1 (May 14, 2005)

I used side cutters to snip the impeller blades. The impeller plastic is black in color and kind of stiff. It wasn't white as pictured on barrreport.com. I moved the Rio 180 higher on the back glass and changed the output nozzle to the flat one that you can change the spray angle. It seems quieter now or, I'm getting used to the sound maybe.


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## Philosophos (Mar 1, 2009)

Strange. Mine was white. Other people's were white too... The conspiracy nut side of me wants to say that they've switched it to prevent the mod, and will push their own needle wheel out for $10 more if things take off.

At the same time, on the side of reason, side cutters are a little brutal. I couldn't get the job done with nonserated fly tying microtips, which are about as sharp as the tissue scissors doctors use. 

If anyone else gets the black impellers, maybe they'd be willing to test with a hobby knife or scalpel to see if that works.


-Philosophos


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## bosmahe1 (May 14, 2005)

In hind site, side cutters were perhaps "brutal" but I think that was how Tom Barr explained it on his site. I might buy another Rio 180 since I found a site that has them on sale for $10.00. Hopefully, it would have the white impeller. Its worth it to get another one since a replacement impeller would be $5.00 and shipping charges would probably be $8.00 for either option.


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## apm (Jul 1, 2009)

I have a 15 gallon with a nano diffuser from ebay and it works flawlessly with my diy


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## Philosophos (Mar 1, 2009)

Ya, that's what he used. I'm not sure how he did it; perhaps he was using a larger impeller. He mentions cutting the blades 3 times on one, and he does tend to keep decently large tanks.

-Philosophos


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