DIY CO2 Question?

[TrashmanTodd]

Hey All,
I've been using DIY CO2 for quite a while now, and pretty much been using the same receipe. I use a coke bottle half filled with filtered water, add a cup of sugar, and shake it to disolve. Then I add 1/4 teaspoon of yeast, shake it a little bit to mix in the yeast. That has always worked for me but lately I've been having a little trouble. I've been usung three bottles on one tank and have the same problem in all of them. They just don't make any bubbles. If they do make bubbles it's only for a day. I keep the holding tank they're in at about 80 degrees, is this right. Other than that I can't figure out why this would happen all of a sudden.

Any Help All?

Thanks,
Todd Miller:D

[Starry]

For one thing, you don't need filtered water. Tap water will do.

Your recipe sounds fine, except I'd go with the Jell-O method. It's worth the 5 minutes of extra work and it will last 2-3 months. For a recipe, check http://aquaplants.web1000.com/art1.html or search AC or the web different methods.

But anyway, to answer your question, it could be old yeast. Buy a new package and try again. Possibly you're adding too hot water, that can kill them.

[Matak]

Some tips:

* Try using hot water to dissolve your sugar. After it has cooled, try sprinkling the yeast on top of the mixture without shaking.

* A bigger (three to four litre) bottle will help make it last longer.

* Use fresh wine yeast (ask for champagne yeast or for something close) each time you batch. The two DIY wine stores in my town both sell little packets of yeast for a buck and change each.

* Fill a spray bottle with warm soapy water and spray all your joins and connections to test for leaks. Leaks will create active bubbles. Never let any soap get into the fish tank!

* Rinse each bottle with a mild bleach solution after each use. Dechlorinate the bottles before re-use!

HTH:)

[TrashmanTodd]

Yea,
As far as fresh yeast goes, it's brand new. I even tried disolving the sugar with hot water and letting it cool, still no luck. And as far as leaks go I've checked the whole system, it's all fine. It's just really wierd.

Todd

[cpr4cpu]

look for a snail in the works. I had a three way tap, and somehow a snail got in the works and plugged the airline. I have also had the CO2 corrode the check valve "flapper".
My point is to check the lines and make sure that they are clear and clean. If the system is being forced to generate more pressure in order to push the bubbles through, you just might not be getting enough "oompfh"
I've had to replace the check valves annually due to corrosion, on eof which had a rubber seal that was all but dissolved by the CO2.

[Booswalia]

Are you cleaning the bottles really well before you refill them. A small bleaching and good rince might help.

[TrashmanTodd]

I thought I was cleaning them out pretty well. I would use boilling water and shake it up. Then I would let it cool to room temp. I checked for leaks and it seemed fine, but if there was a clog in the line wouldn't just blow the line out from pressure instead of just sitting there?

Todd:)

[Matak]

Depends how good your seals are. If all your seals are snug and sound, they should be able to handle the pressure. (at least that's what I think)

[corvettekid82]

Im no expert (just started my first DIY CO2 today) but here's a little trick that worked for me.
Before adding your yeast to the mixture of sugar and water (I used jell-o as well) rehydrate it if its dry. Just mix your yeast with 1/4 cup warm water. I used a candy thermometer to get the temp of the water RIGHT at 106*F. Too hot and you'll kill the yeast. Stir the yeast into the water very well and add a pinch of sugar and stir till disolved. Let this mix sit out in the open air for about 10 minutes for it to obsorb oxygen and begin fermenting and THEN add it to your sugar mix. This worked wonders for me and my Soda bottle was producing bubbles inside of the tank in less than an hour!

[mogurnda]

In a related question, my buddy the yeast biologist was aghast that I don't add any minerals to the mix. Has anyone seen better performance with a little Ca, Mg etc?

[corvettekid82]

Good qustion, and I thought of this too... Why dont you ask your friend what he suggests adding to the mixture and experiment some. We know that Kh and pH give us the relitive CO2 production, so you can measure the results yourself.
You can read some about these debates here: DIY CO2 (http://www.qsl.net/w2wdx/aquaria/diyco2.html)

Here's the part that he speaks about additives:

"There also has been some discussion on adding other nutrients to the mixture to help the yeast grow and multiply. This is an area I have not researched directly, but may be of interest. Nitrogen seems to be a nutrient that yeast utilizes. Unfortunately the research I have gleened showed that nitrogen is used by yeast only when it is in an aerobic environment, not the anaerobic environment we are putting it in. I have not seen any direct research that showed any nutrient other than sugars are used by yeast in anaerobiosis. "

[carpguy]

The link CorvetteKid gave is a great article on DIY CO2. Over at AquaBotanic Annonapersona (who sometimes visits these parts as well) has a great thread on DIY CO2 that includes a bit on yeast and yeast nutrition.

I started to get into researching yeast because of that thread (eventually abandoned it and went pressurized). There is a lot of very good and well-tested info out there… if you start to bang around the homebrew and DIY winemaking sites. Those folks figured all this stuff out way back when, no need to reinvent the wheel.


I]mogurnda wrote:[/I]
my buddy the yeast biologist was aghast that I don't add any minerals to the mix. Has anyone seen better performance with a little Ca, Mg etc?
Um… your buddy the yeast biologist? You need to start pumping this guy for info. The best I could find was a winemaking site :p … A lot of recipes (including the vintner's) call for adding some baking soda to the mix. Since the enviroment becomes wildly acidic and since the vintners will sometimes make it more acidic, Annona and I concluded that its not added as a buffer, but for the benefit of the yeast, that they must be using it to make their shells (and they do have shells (or husks)). There were also notices to not use distilled water as the yeast would need some natural hardness. Folks who were carrying strains from one batch to the next also mentioned reserving the dead yeast as a source of minerals and lipids.

I also found a lot of good info on the hot water starter method that CorvetteKid mentioned. The article goes into a little bit of detail over why this works and how you can kill off a good portion of the yeast by using cooler (room temp) water. The winemaking sites mentioned temp ranges beteen about 105 and 110, or about as hot as a hot bath (I visited a hotspring out West once where the pools got progressively hotter as you went downhill -- everyone was good with 103, no one could get into the 112 pool, 105 or 106 was hot but bearably so). This is actually good for the yeast and will give you a stronger start. Make a small mix with a good bit of sugar, some baking soda, and the hotwater and stir in your yeast -- give it a few hours and toss it into the main batch when its moving along. The yeast goes into a dormant phase and needs good evidence of a friendly enviroment before its willing to expend energy coming out of it.

The tremendously low pHs and anaerobic enviroment that then switches back to neutralish and aerobic should be enough to discourage most bacteria. Not heating up the mix will also help with this. The two most common wine yeasts, "bread" yeast and champagne yeast, like it between the high 50s and the low 70s: room temp is fine, above that and you'll get faster production, but you may also see bacteria begin to outcompete the yeast. The idea is to have the yeast outcompete the bacteria. This is most important at the beginning, but I'd avoid bleach (could be hard on the yeast if you don't get rid of all of it).

I'd guess that Trashman Todd just got a bad batch of yeast. It happens. Could even happen to several pouches from the same shipment (that were stored in a warehouse too long, or shipped in an overheated truck, etc.) I'd try some new yeast from a different source, and while I was at it I'd try to find champagne yeast -- a higher tolerance for alcohol makes it last longer and its low-foaming, greatly reducing the risk of a foamover incident. Worth every penny extra and really not all that much more.

HTH

[mogurnda]

Wow! Lots of info came in while I was unable to log on.

The best I could find was a winemaking site
Try looking into the fascinating world of genetics. There are many labs working on them, the biology is extremely well known (but not by me), and S. cerevisiae's genome is even sequenced. Half our lab used to work on yeast, but that's ramping down.

As far as the yeast biology, the yeast guys here use a broth called "YPD," which gives excellent growth. In the old days, they made it, but now they buy it, so I have to dig around for the recipe. My friend also mentioned that yeast aren't all that fond of dextrose, which is what most of us use.

In reality, it may not be all that good an idea to optimize any farther. First, more growth means that they'll probably max out faster, and we'll have to change bottles more. Also, just using tap water and dextrose I am getting enough CO2 that I'm now worried that I'll need to either bleed it off, increase tank circulation or boost my alkalinity to keep my pH stable.

I have to admit that this is all fairly new to me, but it has been working incredibly well. A little more CO2 and the supplements that plantbrain recommended has given the best sustained growth I've ever had. Plus, the little bit of BBA that was left is slowly fading away.

Recipe soon.

[mogurnda]

Well, after all that, it looks like YPD is mostly yeast extract and dextrose. I suppose the lesson is that yeast contains most of what yeast need to grow:rolleyes:

For double-strength YPD:
Place in a 2L Erlenmyer flask:
20 g Bacto Yeast Extract (Difco #0127-17-9)
40 g Bacto Peptone (Difco #0118-17)
40 g Dextrose (Difco #215510)
0.6 g L-Tryptophan (Sigma #T-0254)
Water to 1 Liter

I'll poke around for better-defined media, but it looks like the main thing missing from the usual sugar solution is nitrogen, like corvettekid82 said.

[TrashmanTodd]

The wierd thing is, I was fooling around the other night and checking all my connections. The connections were fine, no leaks anywhere, but when I turned off or down a vaulve on one of the bottles the bubbles would start comming out again. Go figure! With no leaks in the system! ANY IDEAS? Could it be with three bottles on the system it can't build up enough pressure to push co2 out through the powerhead. I don't know just a guess.

Thanks all, this thred has helped alot.

Todd:D

[djlen]

Trash, if you have no leaks you should get bubbles coming out of a power head within 30 minutes. There's got to be a leak somewhere. The only other thing it could be is bad yeast.
I can't figure out what you mean by a valve on the bottle. You run the tube directly into your power head.
Do this:
2 cups sugar
1/4 tsp. yeast
1/4 tsp. baking soda
Fill the 2-liter bottle 1/2 full with tepid water(not hot)
Pour 2 cups sugar in and 1/4 tsp baking soda and shake the sh*t out of it until totally dissolved
Now add the 1/4 tsp. yeast and shake some more. You want lots of air in with that yeast to get it started
Fill bottle to about 4" from top and set aside for a moment....
Take a small container and put 1/4 tsp. yeast and 1/4 tsp. sugar in it.
Add 2'' of water and stir vigorously for 1 min.
Wait 10mins. and pour the contents of the small container into the 2-liter bottle and seal (with a bottle cap that has no hole in it like the one that was on the bottle when it came from the store) tightly. Let it sit for 30 minutes, sealed and when you take that cap off it will burp, just like an unopened soda bottle from the store does. This tells you that it's ready to go.
When you go to put it on the tank you'll replace the reg. bottle cap with the one that has the tubing through it and set it on the tank

The bottle should not have any valves on it. A hole with the tubing coming out of it that will go directly into the bottom of the power head is all you need. Once in place the tubing should have a good seal and have NO leaks. If it doesn't leak and the yeast is good I guarantee you CO2 in 30 minutes.
For two bottles link them together with a "T" connector and you'll have CO2 in 15 minutes.
This has never failed for me.
Some people put a one way check valve between the bottle and the tank. I've never used one myself. Your choice.
Len

[djlen]

When I started with DIY CO2 I tried sealing the tube that goes through the bottle top with aquarium sealer, hot glue and a billion other substances that, at best worked for a few bottle changes. Then someone turned me on to "bulkhead fittings".
They are used in model airplanes to feed fuel from the gas tank through the bulk head to the engine. They are plastic, cheap, and very, very effective. I have never had a leak while using them and don't have to be SUPER careful changing bottles when using them. You can buy them here:
http://towerhobbies.com
Type in 'bulkhead fittings' in the search window at the top and scroll down to the fittings. I think they are $3.79 for a package of two. I use the small ones. Get a couple of packages especially if you are using more than two or three bottles on your tanks. Two reasons. It's good to have spares and the shipping cost more than the items.
Since it's the only area that can possibly leak CO2 on my set-up I feel it's an important item to have.
Len

[TrashmanTodd]

Sorry about that, I have all three lines going to one vaulve body. Then I have one line going to the power head. I can control the flow off the vaulve body. When I turn the flow down on one bottle I start getting bubbles. When I have all vaulves open all the way I get no bubbles. I thought it was a leak but I've checked every line and no leaks.

Todd

[mogurnda]

Are you sure the valves don't leak when open? If each leaks a little, they would add up to a bigger leak. Some of the cheap valves I have leak more as they are opened.

Another good source for fittings is Small Parts Inc. They have tons of neat stuff for the DIYer.

[corvettekid82]

Whoa, what a plethora of information! While we have all the DIY experts attention... maybe you can answer my newbie question. How long does it usually take for the pH and KH levels to change enough for a rise in CO2 to be noticed? Keep in mind; I JUST started my 1st CO2 bottle on Sunday. It raised my CO2 levels from 4ppm to 8ppm. This is a nice improvement and I'm very happy with the result (especially since I DIMyself :)), but will I need to add another bottle of CO2 to make the concentration go higher?

Tank info (incase you need a little more insight)
46G Bowfront
pH 7.4
KH 7
Ammonia 0
Nitrates 0
CO2 8

The bottle is running to the intake tube of my powerhead, and being fed through the impeller and spends a good amount of time under water before disappearing or floating to the surface.
Thanks to everyone for the help!

[djlen]

Trash, why do you feel you need to control the flow? Every extra gadget you have on line is a potential for leakage. Why not just run them straight into the power head?
Vette Man, I have a kH of 3.5 in my 40 gal. and use two bottles to just get into the low 20's ppm. If you don't see any improvement in your ppm, IMO, you should consider another bottle on line. BTW, I also use a power head to inject.
Len

[TrashmanTodd]

I'm really not trying to control the flow. I keep them open all the way. I was just screwing around, turned the flow down on one of the bottles, then next thing you know I had bubbles. Then I checked that line from the bottle and no leaks. I then checked the rest of them and still no leaks. That's what is making me wonder. Why would it change if you close one of the inlets just a little bit. Some how it's changing the pressure, I just can't figure out how. Better yet maybe I should just accept it.:D

Thanks,
Todd