Corigan

Baking soda is also supposed to make the mixture last longer. I always put baking soda in my mixtures as well.

Matt

Sir_BlackhOle

Baking soda? Thats one I havent heard before. I have been using 2 cups of sugar and 1/2 tsp yeast in a 2 liter bottle. How much baking soda do you add?

dennis

Generally aabout the same amount of baking soda as yeast works well for me. The baking soda seems to slow down the reaction adn it also raises the kH( and thus the pH) of hte mix so the yeast can work longer before it gets to acidic and kills the plants. My mixes generally last 3 weeks before replacing. I am also trying something new. Check out my thread in the DIY section "DIY Pressurized CO2". Just use at your own risk. I make no promises or claims. Works well for me though.

bms

There are a lot of recepies out there for the mix... I am currently using 3/4 of a cup of sugar, 1 tsp of yeast on roughly 1 liter of water. Does that sound OK?

In regards to adding baking soda to the mix, if I understand correctly the BS will increase the production of CO2, therefore making it necessary to add something to control the preassure on the bottle and the amount of CO2 delivered to the tank. Is this correct or does it only make the reaction last longer withouth increasing the production of CO2 at a given time?

gpodio

I think you meant to say before it kills the yeast.

In general, CO2 production from a DIY setup will be quite high at first and then slowly taper off as the days go by. This makes it hard to maintain a constant CO2 level and people need to resort to tricks such as pushing the micro bubbler (if you use one) deeper and deeper each day to increase the amount of CO2 that is diffused as the rate of production drops. Baking Soda seems to even things out and provide a more stable CO2 production throughout the lifetime of the bottle. A more effective method, yet more work involved, is to use a Jello mixture. The jello makes the sugar available to the yeast a little at a time, therefore maintaining a more stable CO2 output. In this case, the amount of water used is very little so you often need to tip the water out, add some more with some fresh yeast until all the jello is consumed.

Giancarlo Podio

bms

Giancarlo,

Jello... interesting, could you comment on the specifics of the "recepie" for the mix you use or have used and your personal experiences with it?

Thanks!
~Benicio

gpodio

I only used this a couple times to see how it works, in the end however I needed as much CO2 as I could get so I ended up using the traditional method without any kind of stabalizer.

The jello bottle:

- Prepare some jello following regular recipe on the back of the box
- avoid eating it
- pour the liquid into the bottle and place it in the fridge as the instructions tell you to do
- once it's hardened, activate some yeast in warm water and pour it in the bottle
- The more water you add the better as it will quickly turn to alcohol and spoil the yeast
- when the yeast is dead after a few days, simply tip the water out and add some more water and yeast until all the jello is all consumed, then start all over again

I think it works best for smaller tanks where you don't need all the CO2 produced by a traditional 2lt bottle, it produces less CO2 but it's stable and lasts longer.

Someone posted a much better description once... somewhere, if I find it I'll copy it here.

Hope that helps
Giancarlo Podio

bms

did a search on google and came up with this:

I am going to try it out. I read somewhere else that one needs one of these bottles for every 30 gallons of water.

gpodio

Again, it depends on your efficiency of diffusion and loss. I was able to run my 55 gallon tank on a single bottle, but I had no surface agitation and 100% diffusion rate.

Giancarlo Podio

bms

OK guys... I had not seen the table until today (I did not have a way of measuring PH).... now I measured my PH it is at 7.0 but have no way of measuring my KH... do I need a test kit for that?

I had my water tested yesterday at my LFS.. they said it was to hard and told me to ad salt... does this have anything to do with KH levels?