diy co2, trials n stuff

[Vinnie]

well I got bored so decided to try some different yeast mix's to try and get different results.

Set up 2 glass bottles with rubber bungs just in case of too much gas builds up, and ran some air tube to a drinking glass to see how much gas i could make.

1st attempt -

3 table spoons of Turbo yeast (brewers yeast, was meant to use the 7 day one, but used the 24 hour one by mistake)

3 cups of white sugar

After 20 min from mixing with about 5 liters of warm water I was get a burst of 3 -5 bubbles every 6 - 7 seconds. 7 hours later came back to see how it was going to find about 8 - 12 bubbles per second...

I'm really glad this test was done with a drinking glass and not one of my tanks lol

I tried to control the gas flow with a tap and 2 outlets but no luck just yet - I have a few ideas to work on so far

[Vinnie]

Well, tried a different yeast last night (the 7 day brewers yeast). After 9 hours came back and had a look, every second getting 3 - 4 bubbles which I guess is still a little to much.

Would that amount of co2 be ok in a 850L tank with say 1.2 meters of air stone running all the time in it to help keep the oxygen levels, or still to much co2 for the tank?

This time I used:

1 and a half table spoons of yeast

2 and a half cups of sugar

Any one got any ideas for me to try, I'm just mucking round trying to see different ways of doing this, and will be adding fertilizer once I have a good mix and seeing if that makes much more of a difference

[N1CK]

it could also not be enough, I think 1/2bps is good for smaller tanks. best way to do it would be getting a drop checker and going from there

[supasi]

No where enough for a tank that size.

What difussor will you be using?

If you use an airstone, most of the bubbles just hit the top and dissapear. Running an airstone to airate the water is just defeating the purpose.Only run the airstone at night.

As Nick said, the only way to see is to add a drop checker and monitor it.

Maybe for you investigations, you should look for better ways to difuse the co2 into the water.

In your jars now your co2 is just bubbling to the surface and not disolving. Bout the only good its doing is creating water movement.

HTH

[breakaway]

I'm pretty sure CO² saturation and O² saturation in water are independent, unless you're putting absolutely ridiculous amounts of CO² into water (like I'm talking so much CO² that it's bubbling off the surface)

Think about it this way - you have a cup of hot water and are making a coffee. First you mix in the coffee, then you add the sugar. Does mixing in the sugar displace the coffee from the water? No. It sweetens the coffee. I.e. both the coffee and the sugar remain mixed in the hot water.

CO² and O² work in the same way.

Maybe for you investigations, you should look for better ways to difuse the co2 into the water.

This has been discussed at length in the previous CO² thread. One of the best (cheapest) ways to do it is to run the CO² airline into the intake of your filter. The CO² bubbles will make their way up into the implellor chamber where they will get bashed around and therefore mixed into the water, ready for plants to use.

[phoenix44]

yes, but water can only hold so much o2 and so much co2. a lot of it is temperature dependent.

if the solution is saturated, it would not allow for any more solute to be added to it.

it is easier for water to hold O2 than it is to hold CO2, and that has to do with the nature of the bonds between Oxygen and water.

[alanmin4304]

As phoenix said, water has a greater affinity for O2 than CO2. In rural areas, particularly over swampy areas of peat there can be a lot of CO2 in well water and this makes the water acid which keeps the iron in the ferrous state and this makes the water taste foul. There are all sorts of expensive ways to correct this but the cheapest is to aerate the water and this converts the iron to the ferric state by driving off the CO2. You need to encourage the CO2 to stay in solution so it is available to your plants (and iron as well) by not aerating or increasing the surface area of the tank.

[Vinnie]

Cool, thanks for all that info.

I have one of those cheap ladder diffusers at the moment but will be buying a better one soon (I hope)

This has been discussed at length in the previous CO² thread. One of the best (cheapest) ways to do it is to run the CO² airline into the intake of your filter. The CO² bubbles will make their way up into the implellor chamber where they will get bashed around and therefore mixed into the water, ready for plants to use.

Yes, I re read that the other day after forgetting about it after seeing it. This is also on my to do list now