# Best method od CO2 diffusion



## Simpte 27 (Jul 16, 2004)

I've been searching the forums (both here and elsewhere) and after all the reading about diffusers, reactors, and whatnot, I've come to the conclusion I have no idea. What is the most effective way of introducing pressurized Co2 into a tank? A powered reactor, a powerhead with venturi loop, a canister filter or a diffuser of some sort (ceramic, glass etc...)?


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## standoyo (Aug 25, 2005)

hi,
imo, size of tank and whether you can effectively camouflage the equipment while getting great circulation round the tank without the plants bending unnaturally?

A powerhead+reactor-pretty good for medium sized tanks and above. just add another per 3 ft of aq width. 4 ft with one is ok but fg plants suffer a bit if circulation is not good.[my experience] no noticeable bubbles circulating except for the plants pearling. does not slow down like canister+reactor overtime.

a powerhead with venturi loop. mr tom bar's invention. very intense pearling on most plants...not everybody's cup of tea but i like it. again circulation important. some experts reccommend using submerged spraybar of canister output to improve circulation. i've just began testing and it will be challenge to see my crypts pearl...

a diffuser. usually not very efficient unless bubbles are very fine or are blown away at diffusor level around aq. again not all people like the bubbles flying around. it also clogs over time and i've cracked two from clumsy handling. IMO good for small tanks but some lfs use this for 4ft tanks. IMO wasteful at more than 4-5bubbles per second est but not really countable[took a peek in their cabinet!]

there's another for xl and xxl tanks but my xp limited here.
usually a small power head+reactor lying inside a sump. some lfs like to use overflow sump tanks that are sealed so co2 does not escape much. the overflow splash is minimised by using some material to let water flow over it smoothly. bonus is the equipment is all in the cabinet...looks very good except for the partitioned area/s for the overflow.

another is to use an external reactor connected to canister or sump...size of aq can be small to large for this type as you can add individual sets of reactor+canister...may be prone to leak but no xp here except for some reading on this.


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## DonaldmBoyer (Aug 18, 2005)

I just simply drilled a hole into my canister filter intake (carefully!), and ran my CO2 tubing into it. You have to put it at or near the waterline for this to be effective. This way, the CO2 is just "sucked" right in with the water into the canister which really helps to get the CO2 into the water as it comes out. I have found this to be the easiest and most effective way to introduce CO2 into the tank....everything else tends to leave the water very rapidly and isn't very effective.

Hope this helps you!


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## houseofcards (Feb 16, 2005)

donaldmboyer said:


> I just simply drilled a hole into my canister filter intake (carefully!), and ran my CO2 tubing into it. You have to put it at or near the waterline for this to be effective. This way, the CO2 is just "sucked" right in with the water into the canister which really helps to get the CO2 into the water as it comes out. I have found this to be the easiest and most effective way to introduce CO2 into the tank....everything else tends to leave the water very rapidly and isn't very effective.
> 
> Hope this helps you!


I did something similiar. I cut off some of the bars of my intake strainer and put a micro airstone right inside the strainer. It seems to be working fine after about 3 weeks and my ph is incrediblly steady. I have a horziontal spray bar which make any fine-tuning on the flow pretty easy. I'm running mine through an Eheim Ecco, which canister are you using.

I didn't understand what you meant that it has to be at the waterline?


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## random_alias (Nov 7, 2005)

I have run a Co2 line into the intake of my Eheim 2026 canister filter.

I have bubbled Co2 through a submerged airstone up into a Co2 bell.

I have made an internal reactor out of a siphon tube and powerhead.

I have run an external AM 1000 reactor inline with my canister filter.

I am about to try using fine-pore stones as diffusers in the outflow of a HOB filter in my nano tanks. 

I have used homemade Co2 in 2-liter bottles.

I have used commercial Co2 yeast/sugar mixes in a commercial bottle.

I have used pressurized Co2.

I'd say the best method is whatever fits your needs and budget. Usually it takes trying one to make you appreciate the benefits of the other. Having said that, I will never use a bell or an internal reactor again and I'll buy an aluminum cylinder and a regulator for a 2.5g nano tank before I'll ever worry about sugar/yeast mixes again. I found those methods total PIAs.

For diffusion, I like the external reactor the best. It also happens to be the most expensive method. That's the way it usually is though.


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## JaySilverman (Jun 19, 2005)

External for the win. You can build one for less then 20$. Plus you know all the co2 is being diffused. You can even run a venturi loop with tiny powerhead to purge any built up gas in the diffuser for added bonus. The best thing about this added venturi loop is you can point this little powerhead at dead spots in your tank. This is the best way to go. Plus it gives you somethign to build! DIY projects is what this hobby is about. For me anyway!


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## Aquaticz (May 22, 2009)

houseofcards said:


> I did something similiar. I cut off some of the bars of my intake strainer and put a micro airstone right inside the strainer. It seems to be working fine after about 3 weeks and my ph is incrediblly steady. I have a horziontal spray bar which make any fine-tuning on the flow pretty easy. I'm running mine through an Eheim Ecco, which canister are you using.
> 
> I didn't understand what you meant that it has to be at the waterline?


Any chance of a picture? I have my Co2 tube shoved up the intake after snipping one bar. I don't get the air stone part. I have two pressurized tanks. The 80 tall looks great & C02 is stable, however I do not trim this tank the way I do the 55. The plant mass is always changing in the 55. That is the part that throws this tank off ( I *think*) So keeping the CO2 diffusion rate becomes a challenge.

I recently started using a very inexpensive drop checker because using a PH meter & the KH/Co2 chart wasn't cutting it. According to the chart my live stock should have died & they did not. So much for the KH/C02 chart..... Ahhh but after fiddling with a fabco needle valve on thye 55 both drop checkers are the same color. Next - I have to wait and see what happens. I am thinking a week or a little better should show results. What do you think? Reasonable way to go or does Ford have a better way to go? CO2 to me is the most important thing to master. I'd like to nail the sucker! What do you think:-k


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## Newt (Apr 1, 2004)

I have an Ehiem 2028 and did the CO2 injection into the intake strainer with disasterous results. I began growing algae on the spray bar that I had never seen before and algae growth in the tank perked up. The CO2 would not always dissolve and would build up in the canister and belch out the spraybar from time to time. The worst part was the o-ring in the outflow sight glass was affected by the CO2 and began leaking water into the pump head and flowed out the handle area. Good thing I have my filter in a plastic tub.

I am now trying a ceramic glass diffuser located just below the intake of a powerhead. It picks up most of the bubbles and chops/mixes them and blows it around the tank. Seems to work well so far.


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## Aquaticz (May 22, 2009)

LOL..... U crack me up Newt.
What size power head might you suggest for a 4 foot long tank be it a 55 or an 80 tall? I have to get educated on the glass diffuser I hear folks mention them quite often. Thanks Newt


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## aquatic_clay (Aug 17, 2009)

i've used all of the methods mentioned except the glass diffuser and my favorite has been the external reactor and using the canister filter with co2 tubing in the intake. i want to try the glass diffusers because i love the way they look and i've heard good things about them.


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## Newt (Apr 1, 2004)

Aquaticz said:


> LOL..... U crack me up Newt.
> What size power head might you suggest for a 4 foot long tank be it a 55 or an 80 tall? I have to get educated on the glass diffuser I hear folks mention them quite often. Thanks Newt


I have a 4ft 75gal. I have a MaxiJet 600 and have it positioned at the spraybar end about a foot out and blowing toward the 'dead zone' under the spraybar so that the current swirls around the corners under the spraybar and out towards the front of the tank.


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## houseofcards (Feb 16, 2005)

Aquaticz said:


> Any chance of a picture? I have my Co2 tube shoved up the intake after snipping one bar. I don't get the air stone part. I have two pressurized tanks. The 80 tall looks great & C02 is stable, however I do not trim this tank the way I do the 55. The plant mass is always changing in the 55. That is the part that throws this tank off ( I *think*) So keeping the CO2 diffusion rate becomes a challenge.
> 
> I recently started using a very inexpensive drop checker because using a PH meter & the KH/Co2 chart wasn't cutting it. According to the chart my live stock should have died & they did not. So much for the KH/C02 chart..... Ahhh but after fiddling with a fabco needle valve on thye 55 both drop checkers are the same color. Next - I have to wait and see what happens. I am thinking a week or a little better should show results. What do you think? Reasonable way to go or does Ford have a better way to go? CO2 to me is the most important thing to master. I'd like to nail the sucker! What do you think:-k


LOL, my post was from 2005, I was probably just getting into pressurized co2. Some folks still use the intake method, but I've pretty much gone to all ceramic diffusers in both small and medium size tanks. In a very large tank you would probably be better off using an inline reactor or multiple diffusers. These ceramic diffusers are like $10 to $20 so it really doesn't pay to run into the intake.


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