CO2 Injection

Are your basic DIY units suppose to act like they are not doing anything half the time? IE going in sperts Currently mine is silent nothing happing at all...could not be any more quiet if it were unpluged with no bottle hooked up...then some time tonight I will look over at it and there are bubbles.

So the question is should it be this intermittent?

And if not what steps would improve it?
Like using different yeast? Or Jell-O? …or shortening the tubing?
 
Ah! Gotcha. No, it should be pretty consistent. Although if you have a "U" in the tubing, like to run it up into a filter intake or a powerhead it can be a little intermittant as water will try to flow into the tube (by gravity) and the gas has to build up enough strength to push it out. It usually results in spurts of very fast bubbling follwed by a couple seconds of repressurizing, the length of which would be determined by the length of the U.

Use Champagne yeast, it's tolerant to a higher alcohol percentage and to a lower pH, I believe.

Here's a recipe that will allow you to re-use the same yeast over and over:
for every 2L:
1 cup sugar
1 tbsp. molasses
2-3 tsp. protein mix
1-2 tsp. baking powder or soda (I use powder, twice as effective plus supplies Ca)

I find that each bottle lasts about 10 days in my appartment which we keep at about 20oC (68oF). Warmer means higher output and shorter life. More yeast means higher output, shorter life. More sugar will increase the lifespan to a limit, but I prefer to just stick to a generous cup. 1c. sugar produces roughly 10% alcohol, champagne yeast can tolerate up to about 19%, but why push it? One packet cost me about $2 and was enough to make 3 bottles (I only made 2 and wasted a bit).

At the end of 10 days use some airline tubing to syphon off the surface liquid trying to keep as much of the gunk as possible (this is your yeast). Since this recipe actually nourishes the yeast, the colony will be growing and every few months you'll need to dump out a little to keep the production rate at a reasonable level.

I use 2x2L bottles linked through a T-juntion, use a gang valve for larger batches, never daisy chain them. That's for a 33g tank, every week to 10 days I change the oldest bottle. So there's always one fresh bottle and one older one. I don't think that the older one has much production, but it does still have a little. Mixing up a fresh batch takes me less than 5 minutes. I have a spare bottle that I just leave aside (from the extra yeast) so that I can brew a fresh batch the day before I need it and let it prime overnight. It's a bit of an art form to get it tweaked just right for your setup, but once you get it setup and working like it should, it's really easy.

Final note: always make sure that the water for the yeast is dechlorinated and not too hot (30oC or lower)
 
2-3 tsp. protein mix? huh?

Like protein mixes used for dieting? or something all together different?


And Thanks so much you have been so helpfull. I suspected the great loop I had in the tubing might have been part of the problem.
 
Hi guys this is my first post here. I've been reading this whole CO2 thread with interest, as I am an enthusiastic proponent of DIY CO2, and I've always wondered about different types of yeasts and nutrient mixtures.

In reading the posts about keeping DIY CO2 bottles warm in cold rooms, the following idea just popped into my head:

Ditch the whole heater/water bath and put the heater *in* the bottle..!!

The LFS's around here all carry those sealed submersiable Hagen heaters, which are only about 1/2 inch in diameter - small enough to fit through the neck of a 2 liter bottle.

But to do this you need to do a little electrical work - and I don't want anyone zapping themselves, so be careful. All you need to do is be comfortable and competent enough to install a replacement AC plug like if you broke the plug off the end of the lamp from your living room or something.

1) Get the smallest of those submersible Hagen heaters, which I believe is 25 watts - which is teensy - 1/2" around by 6" long. I think they might even have smaller ones for fishbowls. The 25w ones cost about 15$ around here.

2) Hack the plug off the end of the cord. NOTE: If one of the blades of the plug is larger than the other ("polarized"), closely examine the wires where you cut the plug off and keep track of which wire goes to the bigger blade. Usually the black wire goes to the small blade and the white wire goes to the big blade - assuming the wires are colored under the jacket, which they may not be. If you have to, put a piece of tape on the wire that goes to the big blade and label it "big blade". I will leave this detail up to the individual.

3) Poke an extra hole in the bottle cap of your 2 liter DIY bottle, and pull the cord through. Leave it hang out enough so it's supended in the bottle at a good depth, but *completely* submerged. You might even want to tie a knot in the cord, or maybe wrap a lump of electrical tape around it where it goes through the cap, so as to keep the heater suspended at the proper height.

4) Spooge up the cord with silicone on both sides of the cap to seal it well.

5) Then take that spare lamp plug from Home Depot or whereever and install it on the end of the cord. As described in step #3 above, make sure you keep track of which wire goes on which terminal, but only if the original plug that you cut off was "polarized" that way.

6) Put the heater in a bucket of water with a thermometer, and let it sit for a while to get it set for about 70 degrees.

7) Slip the heater into the bottle and screw down the cap like usual.

Voila! A DIY CO2 bottle with built-in climate control..!! You could even get one of those little stick-on thermometer decals and stick it right on the bottle to make sure the temp stays around 70 or whatever you want it to be.
 
happychem said:
The best thing that I've found from it is that the yeast at the bottom of the solution can be reused over and over again.

So that tan colored sludge at the bottom of the bottle is the actual yeast culture..? And you can actually leave it there and only change the water mixture above it...?
 
redrocksedona said:
2-3 tsp. protein mix? huh?

Like protein mixes used for dieting? or something all together different?
Yes, that's the stuff. I use the stuff from the grocery store aisle, I suppose I could shop around a little more... But in any case, I read through the ingredients and instructions between a couple different protein supplement powders and picked the one with the most grams of protein per arbitrary serving size (say tablespoon) so that I was adding mostly protein and less flavourings and colourings.

spinjector said:
So that tan colored sludge at the bottom of the bottle is the actual yeast culture..? And you can actually leave it there and only change the water mixture above it...?
If you follow that recipe, yes. That recipe (Tara Nyberg's) provides nourishment for the yeast cells so that they can grow and live. Just sugar water doesn't provide the cells with all that they need, it's like if you tried to live off nothing but rice, you'd get the carbs necessary for energy, but not the protein and nutrients needed to build and repair tissue.
 
I'm looking at putting co2 on my 29gal after I upgrade my lights.
Can I put two 1L bottles, so I can alternate switching them or would those be to small?
 
I use 2x2L on my 33g. I would recomend the same for a 29g, just taylor your formulation to have a little less yeast to start with so that the output is slightly less, mind you it occurs to me that this is a pretty terrible relative explanation since you have no clue how much yeast I use. At any rate, use 2x2L as well and just adjust your yeast quantity so that the output is appropriate to your tank, the batches should last that much longer.
 
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