Yeast and CO2 systems

[Cliff]

For about 2 weeks now I’ve been experimenting with a DYI CO2 system for one of my tanks. I’m currently only using one and somtimes two, 2 liter bottles on a 90 gallon tank. I’ve tried two different recipes for the CO2 producing solution with mixed results. After experimenting with different types of yeasts, I’ve narrowed down the cause of the variation to the type of yeast I’ve been using.

The fast rise yeast gets a lot of CO2 bubbles into the water (about 30 to 40 per minute) but only lasts for around 3 days. The normal bread yeast will last for about a week but only product about 2 to 4 bubbles per minute. The results are fairly consistant between the two different recipes. None of the yeast used had expired and I’ve been using the same bag of sugar and the same mixing process for all solutions tested.

I was going to try some different types of yeast (like a brewer’s yeast form one of those wine making stores) but I was just wondering what brand or type of yeast other members here use.

Any input is appreciated.

[DrNic]

Be careful with brewers yeast. Aside from CO2, they also generate more ethanol than bakers yeast which can easily get into your tank and cause issues.

I found the same difference with standard and fast rising bakers yeast. I ended up using standard for a year or so. I also found that the fast rising yeast needed to be changed more and it didn't seem to be worth the effort.

What recipies are you using? If I remember right I was using 2 cups of sugar, and 1 teaspoon of yeast in a 2L soda bottle. I also added a little baking soda (or baking powder? I can't remember now) in order to keep down the bubbles which helped a lot.

Eventually I moved away from using CO2 though. It was a lot of work and my plants did fine without it.

[Cliff]

Thanks DrNic

I appreciate the heads-up on the brewers yeast. Won’t be using that. Below are the two recipies that I've tried:
A) 1 cup of sugar, 1/4 teaspoon yeast, 1/8 teaspoon baking soda (from Plant Man)
B) 2 cups sugar, 1/2 t yeast (from Laddy Hobbs)

The process I’ve been using is the same one posted by Lady Hobbs, quote below:

“Fill your bottle about half full of the hottest water from your tank and add your sugar to it. Shake it well. I let it sit for about 5 minutes until the solution is clear so I know the sugar is all dissolved. Fill the rest of the way with cold water, add yeast, shake lightly and you're good to go. Water should be lukewarm when you add yeast.”

After I’ve read your post, I was thinking of increase the yeast to a full teaspoon, ½ fast rising and ½ regular yeast.

Might be worth a try.

[Michael Milligan]

I only add yeast the first time. Then dump out 1/2 and refill with water and sugar.

[Lady Hobbs]

Thanks DrNic

I appreciate the heads-up on the brewers yeast. Won’t be using that. Below are the two recipies that I've tried:
A) 1 cup of sugar, 1/4 teaspoon yeast, 1/8 teaspoon baking soda (from Plant Man)
B) 2 cups sugar, 1/2 t yeast (from Laddy Hobbs)

The process I’ve been using is the same one posted by Lady Hobbs, quote below:

“Fill your bottle about half full of the hottest water from your tank and add your sugar to it. Shake it well. I let it sit for about 5 minutes until the solution is clear so I know the sugar is all dissolved. Fill the rest of the way with cold water, add yeast, shake lightly and you're good to go. Water should be lukewarm when you add yeast.”

After I’ve read your post, I was thinking of increase the yeast to a full teaspoon, ½ fast rising and ½ regular yeast.

Might be worth a try.

Me thinks I wrote that wrong. Hottest water from your TAP.......not your tank."

I used 2 c of sugar to 1 t. of yeast.

[Cliff]

We must write alike, I didn't even notice that :hmm3grin2orange:

[Australian natives]

well i cannot seem to get the cap of my filter bottle airtight =P, so i cant say which is more effective, but i have just added 1 cup of sugar, and a whole satchel of standard bakers yeast (i have heard this should last 2 weeks?). and i see lots of bubbles entering filter bottle, but none leaving it. (obviously hot glue gun is not effective as an airtight seal.) gonna use some silicone tonight.

[Michael Milligan]

well i cannot seem to get the cap of my filter bottle airtight =P, so i cant say which is more effective, but i have just added 1 cup of sugar, and a whole satchel of standard bakers yeast (i have heard this should last 2 weeks?). and i see lots of bubbles entering filter bottle, but none leaving it. (obviously hot glue gun is not effective as an airtight seal.) gonna use some silicone tonight.


Got duct tape?

[Cliff]

well i cannot seem to get the cap of my filter bottle airtight =P, so i cant say which is more effective, but i have just added 1 cup of sugar, and a whole satchel of standard bakers yeast (i have heard this should last 2 weeks?). and i see lots of bubbles entering filter bottle, but none leaving it. (obviously hot glue gun is not effective as an airtight seal.) gonna use some silicone tonight.


I had used silicone on my set-up, worked good for me.

[Cliff]

well i cannot seem to get the cap of my filter bottle airtight =P, so i cant say which is more effective, but i have just added 1 cup of sugar, and a whole satchel of standard bakers yeast (i have heard this should last 2 weeks?). and i see lots of bubbles entering filter bottle, but none leaving it. (obviously hot glue gun is not effective as an airtight seal.) gonna use some silicone tonight.


Australian Natives, I was thinking about your comments. When I put together my system, I drilled the holes a little smaller then the hose. I then cut the end of the hose at an angle and pulled it through with a pair of needle nose pliers. I’ve read posts where people have just used a punch to cut a small hole in the caps then pulled the hose through with pliers as well. Both ways you should a air tight seal, but I still put some silicone on to make sure.

If you can’t get your caps to seal correctly, you might want to try that

[Isaac]

Thanks for the advice, I've been trying to get a system up and running, I will follow this closely and see if I can get it going with these tips.

[Cliff]

Thanks for the advice, I've been trying to get a system up and running, I will follow this closely and see if I can get it going with these tips.


Here's a better explaination of how I did mine which also has a link to really good past thread that I found which helped me a lot

[Only Registered Users Can See Links.]

[Australian natives]

hmm, off to buy another bottle of soft drink then ! =P. cheers for the pointers. lets hope i can get it running.
good luck perfecting your mix.