Diy CO2 injection

[sammydee]

Hi there.

Just a quick question - I'm thinking of using yeast toinject more CO2 into my tank, but I don't have any coke bottles. Will a four litre plastic milk carton do it?

Thanks

 

[smithrc]

if you can get it airtight - it'll be fine

 

[sammydee]

It's not likely to blow the cap off the bottle is it? I wouldn't have thought a yeast mixture would be able to produce that kind of pressure but you never know...

 

[smithrc]

it could well do if you let it build up... but it'll be going into you tank!

 

[Yenko]

A yeast/sugar mixture will blow the cap off of anything. A coke bottle bursts at 120 PSI. Imagine 2 liters of sugar water, pressurized to 120 PSI suddenly escaping....

To make my warning more clear, the coke bottle will rupture in one spot first. Then, the pressurized contents will spray out. Sort of like a fire extinguisher.

 

[Nospherith]

I don't have any coke bottles.

Do you have any grocery stores near you?

I guess it would work, but problems like not having a tight enough seal around the cap could lead to having wasted 2cups of sugar. It would be more worthwhile to just get the 2l coke bottles.

 

[sammydee]

Ok if I find a coke bottle I will use it. However, I have been using the milk bottle for three days now and the pressure is not bad at all. I guess that's cos I let it all into the tank. One thing though - although it was producing loads of bubbles at first, now it seems to have dropped off a bit and I don't see any bubbles unless I squeeze the bottle. I got the tube going into the internal canister filter, with the valve wide open, so all that has to happen is for the pressure inside the bottle to overcome the pressure of the water. Its a 20 gallon long tank, so it shouldn't be enough for the water pressure to blow open the milk bottle I wouldm't have thought?

Anyway, the bubble always seem to stream out all in one go. If I give it a little squeeze, hundreds of bubbles come out and keep coming out for ages. They don't come out one at a time by themselves.

Any ideas why this is happening?

BTW my plants are already looking better

 

[Yenko]

You answered your own question about why your bubbles go in bursts not a stream.

 

[sammydee]

Well it doesn't really matter anyway because it is definately working. I measured my pH today and it has crashed from 7.4 to 6.9 in four days .

I am going to do small water changes over a few days to bring it back up, and put a shell in the tank to buffer it. That will work right? The fish don't seem too bothered luckily. I guess it was probably quite gradual over the four days.

 

[sammydee]

Will a calcareous shell help buffer the pH back up?