Co2-Mister questions

[Martin]

I set up my mister quite a long time ago, and I am quite happy with it.. here comes the but:

My bubbles don't seem to travel very far from the mister output nozzle.

The GpH is more than adequate, but the bubbles hit plants quite fast, and start rising to the surface sooner than I would like.

How do you guys setup the mister. Do you clear a sort of path for the CO2 bubbles, or do you let the spraybar take care of the rest of the bubbles? I do, and it gets circulated, but not near as well as I'd like.

 

[VaughnH]

Re: Co2-Mister questions

I gave up on using a spray bar when I found that algal growths inside the spray bar would interfere with the flow of microbubbles, allowing them to form much bigger bubbles before being sprayed out. Now I have a powerhead, a Maxijet 600, with a sponge filter on it, the powerhead mounted with the sponge on top (upsidedown from the normal powerhead mounting). I stick the CO2 line thru the sponge into the pump inlet, where the rotor chops the bubbles into tiny microbubbles. The outlet from the powerhead, with a flow deflector on it to reduce the force of the flow, is aimed about ten degrees forward from the back corner of the tank. The whole thing is down very low in the tank. The flow is strong enough that the plants that get in the way are blown back out of the way. Thus, the bubbles swirl all over the tank.

I lose a lot of CO2 because of the strong water current, and the surface movement, but CO2 is cheap, so I don't care. I get pearling in my 29 gallon tank about a half hour after the lights and CO2 come on in the morning, and by the time they go off again I have everything pearling - big leaf plants pearl quarter inch bubbles and fine leaved plants pearl tiny bubbles. It almost looks like champaign by then. Some people don't like that appearance, but I enjoy it.

 

[quenton]

Re: Co2-Mister questions

I gave up on using a spray bar when I found that algal growths inside the spray bar would interfere with the flow of microbubbles, allowing them to form much bigger bubbles before being sprayed out. Now I have a powerhead, a Maxijet 600, with a sponge filter on it, the powerhead mounted with the sponge on top (upsidedown from the normal powerhead mounting). I stick the CO2 line thru the sponge into the pump inlet, where the rotor chops the bubbles into tiny microbubbles. The outlet from the powerhead, with a flow deflector on it to reduce the force of the flow, is aimed about ten degrees forward from the back corner of the tank. The whole thing is down very low in the tank. The flow is strong enough that the plants that get in the way are blown back out of the way. Thus, the bubbles swirl all over the tank.

I lose a lot of CO2 because of the strong water current, and the surface movement, but CO2 is cheap, so I don't care. I get pearling in my 29 gallon tank about a half hour after the lights and CO2 come on in the morning, and by the time they go off again I have everything pearling - big leaf plants pearl quarter inch bubbles and fine leaved plants pearl tiny bubbles. It almost looks like champaign by then. Some people don't like that appearance, but I enjoy it.

I used to diffuse my CO2 this way too, but I ran into a problem. The main water intake of the maxijets got blocked with a few dead leaves etc, and with the CO2 input coming after the water intake, the pump started to drag from my DIY bottles which then collapsed. So I went away from this form of diffusion -- but I do miss the mist output.

Are you injecting or DIY'ing?

 

[jonathan11]

Re: Co2-Mister questions

Good to hear about varying results from CO2 misting/dispersion. I have tried about every conceivable way of CO2 distribution, and haven't really been satisfied totally with any of them. The spray bar sounded good, seemed to work better than the reactor, but flow decreased, there was a problem in positioning the holes in the spray bar for dispersion, and I went looking for a better way. I want to mention I used 2 Rio 600 RVT pumps in my 75, with a manifold and 2 separate needle valves carrying CO2 to each pump. I've tried the air stones, although not the limewood ones. I finally decided to hook a separate CO2 input line directly to each pump, mount the pump to the lower back wall of the tank with the flow of the pump blowing toward the front of the tank. The pumps are mounted in the left and right middle third of rear wall. My controller pH sensor is mounted in the middle of the rear wall. Misting is excellent, but I've experienced the same problems as the rest of you have. Unfortunately, CO2 is lighter than water and rises-it just doesn't want to stay submerged and allow itself to be swirled around the tank forever with powerheads. Grrrrrr!! I will make an extraneous comment about the location of the controller's pH probe. As often as I've heard this, and how obvious it seems, locate the probe away from the direct flow of CO2-otherwise some VERY erroneous results will occur, such as shutting off CO2 flow when the actual pH of the tank is NOT what the controller is set to. I had good drowth with the probe located near the CO2 output, but what a difference now. That slight bit of algae that would stay on my annubias is completely gone. They have never looked better, and are growing like stem plants.
I would still like to hear more comments about CO2, this is probably the most least understood and most difficult part to get right. :gw
Walter

 

[VaughnH]

Re: Co2-Mister questions

Quenton, I use pressurized CO2, a Milwaukee combo regulator and a DIY bubble counter, which I rarely look at now. The bubbles hitting the powerhead rotor make a chugging sound so I get an audible measure of bubble rate.

 

[Tom Barr]

Re: Co2-Mister questions

I used to diffuse my CO2 this way too, but I ran into a problem. The main water intake of the maxijets got blocked with a few dead leaves etc, and with the CO2 input coming after the water intake, the pump started to drag from my DIY bottles which then collapsed. So I went away from this form of diffusion -- but I do miss the mist output.

Are you injecting or DIY'ing?

This issue is easily resolved.
Turning the CO2 off(actually, the powerhead) at night lets the leaves float up, a sponge prefilter also prevents anything from clogging it.

The other thing is to use a 2-4 liter rigid juice bottle instead of those flimpsy coke 2 liter bottles than can collapse.

No powerhead you might use for a DIY set up has enough suction to collapse those bottles.

You might consider the internal DIY reactor on the site here.
These work very well and are small. They are very easy to use AND GET VERY CONSISTENT RESULTS WITH DIY.

Regards,
Tom Barr

 

[Martin]

Re: Co2-Mister questions

I don't actually use the spraybar for my mister. What I meant was that the bubbles rise from the powerhead, and get caught in the spraybar current.

Perhaps I should look into pointing the mist towards the front glass..

 

[Martin]

Re: Co2-Mister questions

It strange, but I'm having alot of trouble actually finding pictures of people's different Co2 mister setups.

Are they all... or?


I'm curious to see what different solutions people are using, for instance, I saw this and wondered:

http://photos1.blogger.com/blogger/6712/1759/1600/mistreaktorn.jpg

What's with the tube? It's not a reactor according to the site. it says there's no venturi loop, and the powerhead is fed the CO2 Directly. it says that the tube is from a Hagen bell for removing waste in substrate etc.

So what's the deal? do the mist exit into the tube and find it's way out and around the tank?


What I'm trying to accomplish is circulating the mist around the whole tank, and not just in the immediate area of the mister. Leaves and plants stop the bubbles quite effectively. Some of the mist does reach the other side of the tank, but _very_ little.

http://www.petplanet.co.uk/product.asp?dept_id=1238&pf_id=4943 this is the powerhead I'm using..

is it not enough?

 

[VaughnH]

Re: Co2-Mister questions

Here is a photo that shows the system I use to get CO2 mist:

The sponge is a section of a Penn-Plax Cascade bio-sponge, which comes with a hole down the middle that fits over the sponge support grid on the powerhead. I cut a small piece to plug the hole at the top, to stop water bypassing the sponge, and I stuck the CO2 tube thru that plug, into the sponge support grid. Notice I had to use the output flow deflector to reduce the water blast from the powerhead. The powerhead is a Maxijet 600.

 

[quenton]

Re: Co2-Mister questions

Here is a drawing of what I USED to use until it collapsed my bottles due to blockage of the water intake. I may try it again because I liked the mist effect.

I now have 3 of tom's venturi design, although I don't think the venturi works, they certainly raised my CO2 -- but not as good mist.

 

[Martin]

Re: Co2-Mister questions

excellent.

keep 'em coming.

quenton, you didn't use an airstone or anything?



VaughnH, I'm considering the sponge, but I'm worried that it might lower the output GpH too much..

Might try and find a more coarse sponge.

 

[VaughnH]

Re: Co2-Mister questions

excellent.

keep 'em coming.

quenton, you didn't use an airstone or anything?



VaughnH, I'm considering the sponge, but I'm worried that it might lower the output GpH too much..

Might try and find a more coarse sponge.

The sponge I am using is very coarse, so much that I was afraid I wouldn't get much filtration from it, but I do. I doubt that it lowers the flow rate at all, and if it does, it isn't obvious from watching the output. This system solves the following "problems":
No pump input/output tubes in the tank,
No chance of water siphoning out of the tank,
No chance of plugging up the inlet to the powerhead,
No chance of coalescing the CO2 microbubbles in the outlet,
No problem with inadequate water circulation,
No problem with inadequate surface movement,
Easy to redirect the output flow,
Easy filter cleaning,
Low power consumption,
Cheap equipment,
No need for a bubble counter,
No need to provide a dining room table for the shrimp!

 

[Martin]

Re: Co2-Mister questions

Just now I was fiddling with the intake. I wanted to add a sponge to keep crap out of the powerhead. I noticed something I haven't thought about before.

My mister is a powerhead with a short lengt of 16/22 tubing inserted at the intake. Through the 16/22 tubing I run my Co2 tubing, and inside the 16/22 tubing I have my Chopstick diffuser (thx again NIKO). to keep crap out I use one of those intake thingies:

anyway, I never noticed that the intake filter thing actually goes all the way up the 16/22 tubing, not leaving more than a millimeter of space for the water to pass through.

So now I changed it around just to see the difference in flow, and by golly... =)

Anyway, here's some photos to illustrate my weak explanation:

This is what it looked like first:

This is the eheim intake filter thingy.. Notice that the tubing goes all the way to the bottom of the intake, and blocks the current through the filter... DOH..

Then I added the cap for the intake, to give the intake more space for flow.

I then shortened the 16/22 tubing so the mister wasn't sooo large, and took up so much space.
Chopstick diffusion works like a charm.

So this is what it looks like now, seen from behind.

Finally a small vid of the mister in action. Mucho improvement in flow and bubble distribution.
Dont bother mentioning the superb quality of my camera's video function. :gw

http://www.akvarieplanter.dk/images/for webuse/Mist.mpg

 

[quenton]

Re: Co2-Mister questions

excellent.

keep 'em coming.

quenton, you didn't use an airstone or anything?



Might try and find a more coarse sponge.

No, when the bubles from the DIY CO2 went into the intake, the impleller would break them into a tiny stream and broadcast them into the tank -- it became quite a wide spray of micro-bubbles.

 

[Tom Barr]

Re: Co2-Mister questions

If you want to improve the mist and reduce noise when the bubbles hit the impeller, add an air stone for the CO2 below the powerhead or in the intake tube.

The smaller the bubble that hits the impeller, generally the smaller they will exit, less chance for bubbles to coalesce.

Regards,
Tom Barr

 

[defdac]

Re: Co2-Mister questions

Here is my setup:
http://82.183.138.227/files/reaktor.avi

I gave up misting because I couldn't get the mist to spread out evenly. I plugged the loopback-hole with a chopstick (it was laying around so ehmm) and just use it as a regular reactor. But as you can see mist is precipitating out but it isn't spread out far.

Somehow I got micro deficiencies when I did the mist thing. The pH didn't drop so I guess my EDTA/DTPA micro (NutrSi, eqivalent of CSM+B) somehow didn't like the higher pH or something. I had to dose *alot* more than I had been used to before I tried mist and of some weird reason it ended up precipitating in my biological filter media:
http://www.defblog.se/pictures/picture1648.jpg
I renewed it by letting it soak in citric acid and it turned to the regular white form as you can see in the orange bucket.

Now I get the pH to around 6.0 in the middle of the day with a KH of about 2 and the pearling is great.

Ofcourse I can't be sure it was because of the mist my filter media turned dark red, but the fact that acid made it white again and chlorine couldn't bleach it white I think that was what was going on.

 

[Martin]

Re: Co2-Mister questions

Hi Daniel.

Nice little vid

What's the point of the 2 powerheads?

I can't get my head around your setup. The mist goes through the squared piece of filtermaterial? Then goes up the bottle, and bubbles get smashed by the powerhead?

if so, what's the other powerhead doing?


The bubbles sure are small !

 

[defdac]

Re: Co2-Mister questions

What's the point of the 2 powerheads?

I'm sorry, I should have said that the black Quickfilter+Powerhead is just to polish the water. Like a very low-grade diatom-filter. It has nothing to do with the CO2-reactor.

can't get my head around your setup. The mist goes through the squared piece of filtermaterial? Then goes up the bottle, and bubbles get smashed by the powerhead?

It's not misting at all actually. It's just a simple ordinary intank reactor. I just push in CO2-bubbles inside the PET-bottle from below and let the powerhead swirl them around. But as the powerhead is quite strong mikrobubbles manage to escape. Especially later in the evening I see a bit of gas buildup inside the reactor and more "mist" is escaping through the blue sponge. A bit like Tom's open internal loopback-reactor. He uses a L-pipe and a weaker pump to achieve the same thing without a sponge I guess.

The sponge isn't rectangular, it's just pushed in so it's the same shape as the bottle, cyldindrical.

I did kindof a Barr-reactor and it looked like this:
http://www.defblog.se/picture/1611.html
Main difference I didn't have to use a L-pipe inside the bottle and I had my venturi-loopback from the top to acieve maximum of mist without any buildup.

Here is another variant that produced even better mist but as I said in my first post I couldn't get the mist to reach everywhere:
http://www.defblog.se/picture/1628.html
Very easy to make. Just a powerhead on top and a 180 degree scalpel incision on the bottom of the bottle. No gas buildup, just an insane amount of mist. The bottle in this "contraption" is just to collect bigger bubbles and make mist out of them via the venturi-loopback and to spread out the mist 180 degrees from the reactor - this could have been done with just a tiny cylinder instead of a big PET-bottle i guess.

 

[Martin]

Re: Co2-Mister questions

Aaaaaaaah.. I think I get your setup.

The powerhead is positioned on it's side. Right?

http://www.defblog.se/picture/1628.html

The CO2 is misted via powerhead, gets pumped out into the bottle, bigger bubbles rise up, enter the hose again, and gets smashed via powerhead..again, the bubbles that are small enough for the powerhead to push out through the bottle, leaves via the hole in the bottle.


It's impossible to see the hole, so I can only guess that it's a fairly big hole?

So why didn't the bubbles circulate through the tank?

I made mine with out the bottle, so the bubbles just get sent flying through the tank, like in the video.
it rises pretty quickly, but the spraybar kicks it around the tank some more. Some of the CO2 escapes the tank fairly quickly, but I can see bubbles every where I look, but of course alot of it is concentrated where the powerhead is.

Anything you reckon I can do to increase the effectiveness?

Martin
Http://www.akvarieplanter.dk

I'm sorry, I should have said that the black Quickfilter+Powerhead is just to polish the water. Like a very low-grade diatom-filter. It has nothing to do with the CO2-reactor.


It's not misting at all actually. It's just a simple ordinary intank reactor. I just push in CO2-bubbles inside the PET-bottle from below and let the powerhead swirl them around. But as the powerhead is quite strong mikrobubbles manage to escape. Especially later in the evening I see a bit of gas buildup inside the reactor and more "mist" is escaping through the blue sponge. A bit like Tom's open internal loopback-reactor. He uses a L-pipe and a weaker pump to achieve the same thing without a sponge I guess.

The sponge isn't rectangular, it's just pushed in so it's the same shape as the bottle, cyldindrical.

I did kindof a Barr-reactor and it looked like this:
http://www.defblog.se/picture/1611.html
Main difference I didn't have to use a L-pipe inside the bottle and I had my venturi-loopback from the top to acieve maximum of mist without any buildup.

Here is another variant that produced even better mist but as I said in my first post I couldn't get the mist to reach everywhere:
http://www.defblog.se/picture/1628.html
Very easy to make. Just a powerhead on top and a 180 degree scalpel incision on the bottom of the bottle. No gas buildup, just an insane amount of mist. The bottle in this "contraption" is just to collect bigger bubbles and make mist out of them via the venturi-loopback and to spread out the mist 180 degrees from the reactor - this could have been done with just a tiny cylinder instead of a big PET-bottle i guess.

 

[defdac]

Re: Co2-Mister questions

The powerhead is positioned on it's side. Right?

Exactly, turned 90-degrees so it blows straight down into the bottle.

The CO2 is misted via powerhead, gets pumped out into the bottle, bigger bubbles rise up, enter the hose again, and gets smashed via powerhead..again, the bubbles that are small enough for the powerhead to push out through the bottle, leaves via the hole in the bottle.

Exactly. Because I've positioned the loopback so high up, it never got any buildup.

It's impossible to see the hole, so I can only guess that it's a fairly big hole?

The hole is the bright cut/line a couple of cm:s above the bottom of the bottle. It goes 180-degrees around as you can see, to get maximum spread out from the bottle.

The picture is taken before I placed the hole thing where it should be, so the cut is blowing right at the front glass - that's idiotic - it should at least be turned 180-degrees so it blows out in the tank instead of into the front glass, but the placement is just to get a good picture.

So why didn't the bubbles circulate through the tank?

When I placed it on the short side of the tank the mist was blocked by very dense plant groups. I like it dense and it's dense everywhere. I tried pushing the mist around with a spraybar but it was mostly the plant groups near the reactor that had relatively good growth.

I even tried to loose the bottle and just put a spraybar on the outflow of the powerhead and placed the spraybar along the back of the tank spraying forwards over the substrate so the mist was relatively evenly spread under all dense plant groups, but no. No action there either.

I made mine with out the bottle, so the bubbles just get sent flying through the tank, like in the video.
it rises pretty quickly, but the spraybar kicks it around the tank some more. Some of the CO2 escapes the tank fairly quickly, but I can see bubbles every where I look, but of course alot of it is concentrated where the powerhead is.

Exactly my headache too. Couldn't figure out to solve it with really dense plantgroups.

Anything you reckon I can do to increase the effectiveness?

*shrug* Don't know.

One thing I think Barrs venturi-design much better is the fact that he has the venturi loop back placed so deep down on the reactor chamber. That means his design do two things: 1) It dissolve quite a lot of CO2 into the water 2) Not until the chamber get a big build up of gas it starts misting.

By the time Toms design starts misting the water will already have much dissolved CO2 that reach everywhere but also spits out mist that collects under the leaves and do additional wonders to the CO2-supply for the plants.

A bit like my design I made a movie about with the big difference that I don't have any good way of distributing the mist to the whole tank.