D.i.y. Co2 Injection.

[Blonde Kid on Morphine]

Hey guys last night I tried my hand at a home job CO2 system.
I got all the info from this page http://www.sydneycichlid.com/diy/diyyeast.html
But I made mine with a little difference.
What you'll need is a 2 or 1.25L bottle and lid
Air stone
Air tubing
Silicone
3/4 cup full of sugar
Warm water
And 1 teaspoon of yeast per system/mix


Firstly instead of a 2L bottle I used a 1.25L thinking that with the same mixture as the 2L I would be getting higher pressures in the smaller container.
Now I only thought to take pictures after it was mostly done, but the other page has some good pics too.

Firstly I took an air stone and 1m of air tubing (I had spare air stones from unused UGF uplift tubes)
I then cleaned the bottle with some hydrogen peroxide (bleach) the beauty of this is it breaks down into oxygen and water so you don't have to clean all the bleach out.
Then I drilled a hole in the top of the lid, put the air tubing in the lid and sealed it all up with silicone and let it sit and cure for a few hours.
When the silicone and air stone were all done it looked like this. [attachment=2230:2005_072...1_resize.JPG]

Then I got my 3/4 cup of sugar and yeast [attachment=2231:2005_072...2_resize.JPG]

and put the sugar in the bottle then put a kettle on and let it get about half way boiling so as not to melt the bottle then added it to just above where the bottle starts getting smaller. put a different lid on if and shook it till the sugar was all dissolved.
Then added the yeast and shook that then placed the lid with air stone back on it and went and put it in the tank.
[attachment=2233:2005_072...3_resize.JPG]

[attachment=2234:2005_072...4_resize.JPG]

Now at this point I thought I had done somthing wrong as it was not bubbling, but then I thought hey the yeast has to start working so left if came back and checked it an hour later and it was happily bubbling away, so there you go!
Keep in mind the warmer the bottle is kept the better the yeast will work.

Tim.

[wombat1100]

Hey there Tim,
good to see you having a go at the co2 injection.
My questions are,
1:I believe you can have too much co2 in the tank and thought you might want to research this as you might need a tap in-line to regulate flow?
2:I have also read that if your cover glass is too well sealed on your tank that you can get a buildup of co2 under the cover glass causing there to be no oxygen there and therefore no oxygen getting absorbed into the water killing your fish.
I did start researching this a while ago but then went of track for some reason?!
just thought u might like to know, I may be wrong also , so if anybody else has some input I would be interested to read it.
Dazz

[Blonde Kid on Morphine]

@wombat: Thats a very valid first point, the system I made from the tutorial I read was said to be for up to 100l tanks and that you would need more systems to get higher levels in larger tanks. Because my tank is 150L I don't feel its necessary to have a regulator on my hose but still a good idea for smaller tanks :wink: .

I have not heard of your second point before tho and will look into it myself :cool: . The entire tank top is not covered however so I think I should be right.
Thanks for the post mate I wouldn't of thought of those things myself hehe.

[wombat1100]

@wombat: Thats a very valid first point, the system I made from the tutorial I read was said to be for up to 100l tanks and that you would need more systems to get higher levels in larger tanks. Because my tank is 150L I don't feel its necessary to have a regulator on my hose but still a good idea for smaller tanks :wink: .

I have not heard of your second point before tho and will look into it myself :cool: . The entire tank top is not covered however so I think I should be right.
Thanks for the post mate I wouldn't of thought of those things myself hehe.[/b]

hey BKOM, i was just readin some more, be real careful of your water perameters aswell, with low kh in our water and soft water the ph could be a major problem to keep an eye out for.
Dazz

[Blonde Kid on Morphine]

yeah I tested my ph last night and it was at 6.8 and am going to check it again soon to see if its shifted much.
cheers :wink:

[GoGuppy]

Hey there Tim,
good to see you having a go at the co2 injection.
My questions are,
1:I believe you can have too much co2 in the tank and thought you might want to research this as you might need a tap in-line to regulate flow?
2:I have also read that if your cover glass is too well sealed on your tank that you can get a buildup of co2 under the cover glass causing there to be no oxygen there and therefore no oxygen getting absorbed into the water killing your fish.
I did start researching this a while ago but then went of track for some reason?!
just thought u might like to know, I may be wrong also , so if anybody else has some input I would be interested to read it.
Dazz[/b]

Hi Daz



When I was using a sugar yeast mixture for adding CO2 into the tank, I used a small plastic diffusion bell, which is basically an inverted test tube like container (but preferably wider and shorter) from where the CO2 slowly dissolves into the water. Any XS CO2 just bubbles away and so it was almost impossible to overdose the CO2.



Before adding a flow regulating tap in the CO2 line, it may be useful to reflect on BKOM's comment regarding the yeast-sugar mixture working better when it's a bit warmer. Other factors also impact on the mixture and every new batch made up will be slightly different to the previous batch, that is the yeast may be fresher, water temperature slightly higher, air temperature near the tank may be warmer, maybe slightly more sugar or yeast in the mix, etc etc. A flow regulating tap will by its nature increase the backpressure in the plastic tube and taken to an extreme may cause the plastic bottle with the mixture to rupture.



With regard to the question on whether a sealed cover is better, I have read a few articles on maintaining a dutch style planted aquarium and they recommended to have a good seal to prevent CO2 from escaping to atmosphere. Similarly, the articles recommend to minimise water circulation in such tanks for the same reason. I've just checked and found that CO2 is 50% heavier that air, thus would likely form a layer on top of the aquarium water if left undisturbed.



The above two measures are obviously counter productive to increasing oxygen levels in the tank (note that one way to increase the pH in the tank is to increase aeration to drive off the CO2!!). Thus you could conclude from the above that there is a trade off in a densely planted aquarium with regard to the stocking level of fish you could have, as compared to an unplanted or a lightly planted aquarium. Food for thought????



One last suggestion, consider adding a one way valve in the CO2 supply tube to prevent back flow from the aquarium in the case of the tube coming undone from the bottle or the bottle leaking.



Cheers and happy gardening



Peter

[wombat1100]

Hi Peter, I was doing some more resaerch last night and came accross the bell type diffuser for Co2 as you describe, also directly inputting it into a undergravel filter via a power head and also through the canister filter via the intake hose inside the tank for the canister filter,apparently the canister filter theory almost completely disolves the Co2 in the process.
All food for thought i guess, like you say it seems one thing is a trade off for the other.
Dazz

[joz]

With adding CO2,just be careful with your KH.Because as you add CO2 the ph will drop without something to stabilize it.Then at night if you switch it of it may climb again.Tanks have been known to crash as the carbonic acid is added to the water by the CO2.
When adding the CO2 the best thing is to make sure the bubbles are small and kept in suspension as long as possible in the water,its this way the gas is absorbed into the water.
Also remember because you've added CO2 it doesn't mean that it drives the oxygen out,both can be dissolved in the water at once.

When using CO2 make sure you have enough plants in the tank to convert it back to oxygen.You can see the plants actually releasing fine oxygen bubbles steaming from the leaves when the tank is balanced properly.This also means having adequate lighting for the whole photo synthesis process.BTW fertilizer also helps here.

When all this is working properly youd better get ready for some serious gardening. :)

[GoGuppy]

When using CO2 make sure you have enough plants in the tank to convert it back to oxygen.You can see the plants actually releasing fine oxygen bubbles steaming from the leaves when the tank is balanced properly.This also means having adequate lighting for the whole photo synthesis process.BTW fertilizer also helps here.

When all this is working properly youd better get ready for some serious gardening. :)[/b]


Yeah, it's great when you see the tiny oxygen bubbles from the plant leaves streaming up towards the surface, you know then it's all working as it should!! :biggrin:

Cheers

Peter

[Blonde Kid on Morphine]

Well a week on and my plants are a bit happier but somthing else has become clear to me now.. the plants do enjoy the CO2 but given that I don't have optimal lighting for my tank the algea likes it even more haha so I have pulled the setup out of the tank untill I can get enough lighting for the plants to really take off with it all.

[GoGuppy]

Well a week on and my plants are a bit happier but somthing else has become clear to me now.. the plants do enjoy the CO2 but given that I don't have optimal lighting for my tank the algea likes it even more haha so I have pulled the setup out of the tank untill I can get enough lighting for the plants to really take off with it all.[/b]

Hi BKOM

Yeah, that's a bummer. Not sure which is more important, CO2 supply or adequate lighting?? you really need both for plants to florish.

On the other hand, leaving the lights on too long can also stimulate algae growth, as can outdoor light reaching the tank.

Like most things in life, it's providing the proper balance of all factors that make it work (I know this sounds like a load of bull dust, but there's nothing like trial and error; it's the only way to learn :blush: ).

Good luck with the plants, let us know how you go.

Cheers

Peter