# DIY CO2 -- Size of bottle in proportion to tank



## peterinwa (Sep 27, 2002)

I've posted a dozen questions and your answers always include, "add CO2 injection." I give up! Actually, now I'm excited to try it.

I only have a 10 gallon tank (so far). Does this mean that I should use a smaller DIY bottle than the 1 liter Coke bottle I keep reading about? I would think the size of the bottle should be in proportion to the size of the tank.

And how do you know if the tank is getting too much CO2?

Thanks, Peter


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## GulfCoastAquarian (Jul 30, 2002)

I'm glad to see you've decided to take the next step in aquatic plant care and start introducing CO2 into your tank! You won't regret it!

To answer your questions:
1) The size of the bottle you use for Yeast/Sugar will most affect the length of time for which the Yeast will efficiently consume sugar and consequently produce CO2. A smaller bottle will be able to dissolve less sugar, with less water present. Also, as time passes, a byproduct of the Yeast multiplication is alcohol. Eventually, alcohol levels reach toxic levels and actually kill the yeast bacteria. A larger bottle of water will keep alcohol dissolved levels low and prolong the life of your CO2 generator.
A larger colony of yeast and sugar will naturally also be capable of producing more CO2, but generally you can use as large a bottle as you like. A 2 liter bottle would work perfectly for your 10 gallon tank. A 1 gallon container might last a bit longer, though.

2) If you were injecting too much CO2, reaching levels above 30-40ppm, the fish would respond with signs of stress and disease. High levels of CO2 are toxic to fish. Just as a note - it is pretty difficult to get CO2 levels to toxic levels with a Yeast generator. Even in a small tank, and especially with hard water. If your water is very soft, and the tank is fairly small, it might be possible, though. My 2.5 gallon nano planted tank has a 2 liter bottle generator on it running full tilt into a power filter and levels haven't even reach ideal (25ppm). I can't seem to get them higher than 10-15ppm with my relatively hard water (8 dKH).


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## Jim Miller (Dec 24, 2002)

Don't get a coke bottle, instead get a juice bottle. The juice bottle has a full rather than partial base, has less flexible sides, larger mouth for filling and typically has handholds so it is easier to carry. All of this means you are much less likely to end up with a yucky mess on the carpet due to tipping or spilling or worse in your tank.

Juice bottles come in a variety of sizes. I've seen 32oz, 46oz and 64oz so you can pick the size that fits your needs. I've found that the 46oz works well on my 3 gallon and hides nicely behind it as well. The size you need will depend somewhat on your choice of diffuser. I'd start out with the 64oz and go down in size later if you want. The final size will be somewhat dependent on the level of CO2 you want and the efficiency of your diffuser. No big deal to change bottle sizes...

BTW I've found that the best way to attach the CO2 line to the bottle is to drill a small hole in the top, cut the line on an angle and pull it through the hole with a pair of pliers. This will give you a leak free fit with no glues. The top will transfer among any of the sizes of bottles mentioned.

good luck

jtm


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## SNPiccolo5 (Oct 6, 2002)

> Eventually, alcohol levels reach toxic levels and actually kill the yeast bacteria.


I don't think yeast are bacteria, they are classified as unicellular fungi to my understanding....

About yeast CO2, the bread yeast works fine, but if you can get wine yeast or something like that it will last longer. I haven't done it before, but their alchohal tolerance is higher, and you will get more out of your yeast. Also, if you added "yeast nutrient" then your yeast would last longer. These are just some thoughts... the yeast/sugar/water works great! Good luck with your CO2, it will amaze you!

-Tim


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## Glud (Nov 26, 2002)

Tim, i think it is called champagne yeast. 

When i was using co2 on my 10 gal(i dont have it anymore, my younger brother got it) i only had like 10ppm. I will recommend using =http://fins.actwin.com/aquatic-plants/month.9902/msg00003.html]thismixture

Good luck!

- Glud


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## peterinwa (Sep 27, 2002)

I don't know if I have hard water or soft water. My tap pH is 7.4 and my tank pH is 7.8 or so.

From what I have read I believe I have to be careful about changing the pH too fast. So I thought I'd start with just the open air hose in the tank and see what happens; then add an airstone as the next step; and then build a reactor.

Jim -- That's what I was going to try first. No glue or sealant.

Also I collect crock pots and plan to put the bottle in the crock pot on the floor beside the aquarium stand. So I won't have to worry much about spilling.


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## Buck (Oct 13, 2002)

Just putting the tubing in will do nothing as it will just bubble to surface and dissipate... 
Easiest way for now would probably be to tip a small (heavy) bowl upside down and put the airline under that to trap a larger bubble for now. CO2 needs to have lengthy contact with water to dissolve into it.
... get  yourself a GH/KH test kit to check your water's hardness ... the softer the water the less CO2 you need bro...
KH is the key value... 3 - 4 is ideal... 5 is OK... 6 and higher you need mucho-CO2o to get the ppm of CO2 youi are looking for.
It is pretty impotant to know the KH value before doing CO2 safely in a small tank.
Your plants will love you for it...and your fish will be happier too...:bounce:


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## Jim Miller (Dec 24, 2002)

You won't get much use from an "airstone" they bubbles are way too big. Get a Rena 2" diffuser: they look like an airstone but will produce a very fine mist of bubbles. Other airstones and limewood diffusers don't either produce fine enuf bubbles or do so only for a short period.

Hot tip: cut off the lip of the rubber input gasket as it will collect some of the fine mist into larger bubbles.



have fun

jtm


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## peterinwa (Sep 27, 2002)

When I started posting on freshwater fish forums I was told I HAD to get test kits for Ammonia, Nitrites, Nitrates and pH so I could specify my water parameters. I got those, but of course now that I know what I'm doing (a little bit) I never have Ammonia, Nitrites or Nitrates! LOL

Then I got a Seachem Iron test kit, but it doesn't work well because I am using a Hagen Iron supplement. I'm going to get Seachem Flourish Iron so the Iron and test kit will be compatible.

Now it sounds like to get help with plants I need a GH/KH test kit. I'll have to do my homework because I have no concept of what those terms mean. (Nor do I understand soft or hard or alkaline... or how they relate to pH.)

Anyway, is there one test kit for both GH/KH? What companies make good ones? None of my LFSs sell these so I'll probably have to order them on-line like I did my Iron test kit.

Thanks so much... I'm learning!


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## Captain (Jul 31, 2002)

> _Originally posted by peterinwa_
> Then I got a Seachem Iron test kit, but it doesn't work well because I am using a Hagen Iron supplement. I'm going to get Seachem Flourish Iron so the Iron and test kit will be compatible.


It shouldn't matter if the maker of the test kit is also the maker of the iron supplement. Does it? If the iron in the water is in a plant usable form then the test kit should detect it regardless of the suplement.


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## peterinwa (Sep 27, 2002)

My Seachem Iron Test Kit hardly reacted at all to Hagen Iron, but reacts well to Seachem Flourish Iron.

But here's something else I learned from talking with the Seachem rep.

You are supposed to maintain a level of about 0.1 mg/L Iron, and I'd assumed that would be on a continual basis. Meaning that anytime you tested you'd get at least 0.1 mg/L. But I couldn't maintain hardly any Iron reading at all, so I called the rep.

Turns out that that's the reading you're supposed to get JUST AFTER putting in the Iron, and that it almost completely depletes during the next 24 hours.

So what's the point of even having an Iron test kit? I haven't figured that one out yet.

I'm adding 25 drops of Flourish Iron in my 10 gal daily and it's going well.


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## GulfCoastAquarian (Jul 30, 2002)

Not a lot of people bother testing for iron (myself inlcuded). If you are supplementing other micronutrients at the same time with a supplement such as Flourish, Yamato Green, Planetx. etc. then you can rest assured iron levels will always be consumed by your plants at the same time as the other micronutrients.


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## peterinwa (Sep 27, 2002)

The Flourish rep says you need to supplement Iron more frequently because it depletes on a daily basis.

So you can use Flourish once or twice a week, but after 24 hours the Iron will be gone from the water. (I have verified this with my Iron test kit.)

Therefore they suggest supplementing with Iron daily. Sounds like I'm the only one doing this, and I still can't grow plants!


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## Buck (Oct 13, 2002)

Potassium deficiency is another thing to cosider when tank is heavily planted...
It is as important as Iron for maintaining the health of plants with high watts and CO2


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## PhishNeslo (Dec 20, 2002)

tetra initial sticks have TONS of potassium. Special K for the tank.


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## peterinwa (Sep 27, 2002)

Do you measure the potassium in your water with a test kit?


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