DIY CO2 not producing.

[youronlysin]

Hi all. I've done some research and decided to try a diy CO2 setup in a 15 gallon planted tank I have. Im using a 1 litre plastic bottle for a generator and an active reactor powered by a small powerhead. The problem Im having is with CO2 generation. I don't know if Im getting the mixture wrong or there is something else amiss.

In a 1 litre bottle, Im using 2 cups sugar, 2 cups water and 1/4 teaspoon yeast. I used boiling water to dissolve the sugar and made sure it was cool before I added the yeast mixture. For the yeast mixture I used 1/4 teaspoon and dissolved it in a little bit of lukewarm water. Stirred it briskly and added a pinch of sugar and stirred it briskly again. I let it sit for a good 10 minutes before I added it to the sugar mixture. Shook it all well and it does nothing. Its sat for over 24 hours and I still have nothing. If I shake the bottle now, it practically explodes and shoots junk everywhere, but once it settles down it doesnt do anything. This is the second bottle I tried; the first I used a full teaspoon of yeast, but I didnt dissolve it first before I added ti the sugar mix. That bottle didnt do anything either. I got a few bubbles that formed on the top of the mixture after about an hour or so, but no pressure. The second time I figured it would work better due to dissolving the yeast mixture first, but It just doesnt work unless I shake the bottle up now, and that proves to be quite messy. Is my mixture just not right for a 1 litre bottle? I know the mix I have is for a 2 litre bottle, but it all fits with a little room to spare, so I figured it should do something. My yeast is just an active dry yeast in the little packets....it isnt anything fancy just the generic plain yeast. Just wondering why it doesnt produce any gas unless I shake the bottle. Any hints for me?

 

[malkore]

2cups of sugar is too much for a 1 liter bottle. reduce to 1 cup.

It is producing some gas, just not very much. You likely have a leak in your setup...and the smallest leak will cause a DIY to not work, since the pressure is so low to start with.

when you re-hydrate yeast, don't stir it. Just add it, and let it soak up water and sink on its own. After 15-30 mins, you can shake it up ONCE, and once only, to oxygenate the water. Never shake it after that.

 

[youronlysin]

Excellent. Thank you! I'll give it another go...if this doesnt work as well maybe I'll upgrade to a 2 litre bottle. I'll doublecheck the fitting on the lid as well for leaks. It sure produces a lot of pressure if I shake it up right now boy, I thought I was gonna have a real mess for aminute...luckily I had a bucket right next to me. Its a good thing I didnt decide to put the plain cap on the bottle before I did that. I'll give it a go. Thanks again!

 

[youronlysin]

She be workin' now, baby. 8)

 

[TankGirl]

What size hole did you drill in the cap?

(OT) youronlysin - When I get back from my NYC trip next week I will have a giant wad of hornwort that I'll give you if you are looking for plants and are willing to come by and get it. I ought to be able to give you some crypts, too, by then.

 

[youronlysin]

Oooooohhhhh!!! Yay!!! You bet...I'll find some time to do that.

The hole in the cap is just big enough that an airline coupler fits tight inside it. It isnt sealed with anything at all....just press fit. The whole thing is working now just fine. Im getting about one bubble every three to four seconds into my powered reactor.

 

[TankGirl]

Cool. I'll let you know when I get back about the plants.

 

[frog girl]

if you have a hot glue gun they are perfect for sealing the airline. This will help at the end of the 2 weeks or whatever when your mixture isn't producing so much. Also its pretty important to keep the blue gasket that the put in the top of the lid. That is what really forms the tight seal there.

These are just in case strategies. Glad its working now.

 

[youronlysin]

Ohh. Good info. I left the gasket in place, but I never thought about using my hot glue gun. I could use some clear silicone, but I didnt think it would stick to the plastic cap.

 

[shawmutt]

On my site I have a really good way to test the bottlecap for leaks

 

[youronlysin]

Pretty snazzy. I like the dual bottle setup...now if I could do that with beer bottles....ahh never mind. That'll be a different post.

Im ok for now...I do plan on re-doing the whole setup, but I wanted to see what kind of results I could get from the plants. Im getting good production now that I re-mixed the solution, and I dont have any excessive pressure anywhere to cause any problems so far. Its just wide open straight into the reactor..last I checked, I was getting about one bubble every four seconds, but Im not concerned with maximum efficiency just yet. I just want to get it in the tank for a while and take some measurements. The stuff is cheap enough I can carry on for a little while this way. I was more concerned with testing the reactor to begin with and I think Im going to make some changes to that already, so I'm on the right path. The tank is small enough I think the diy setup will work out great for me.

 

[TankGirl]

Yes! I had forgotten, Shawmutt - I think that is so clever.

 

[youronlysin]

Almost a year ago I started this post. I just dont feel like writing a whole new one to discuss an old issue I guess. Anyway, the setup was working fine for the longest time even without using any sealant on the caps....the fitting was just press-fit into the cap. I could get a months use out of a one liter bottle every time. I finally used a different brass fitting in the cap and sealed it all up with aquarium grade silicone just for good measure. My problem is now that Im back to no output again. Im using the same mixture I always did and doing it all the same way. There seems to be some production going on in the bottle, but it isnt nearly as powerful as it used to be. Do I need to sterilize the bottle between fillings? Could this be degrading my performance? I cant sterilize with boiling water because the plastic bottle just melts (found that out the hard way). I even tried using new packages of yeast with no luck. I can blow through the line just fine with my mouth so there isnt an obstruction or anything. I cant think of anything that has changed, but I need to fix it soon...the plants are showing the effects already. Anyone have any advice?

 

[TankGirl]

Glad to hear from you again!

There are several things that could be happening - bacteria in your bottle preventing vigorous gas production, or there is a leak somewhere. You could try replacing the soda bottle more often and/or using an extremely weak bleach solution to rinse out the bottle in lieu of using boiling water to sterilize, and at the same time check carefully for leaks. You could consider removing the old silicone and replacing it around your brass fitting, and also consider replacing your airline tubing, since it is relatively cheap and could have been degraded by the CO2 gas somewhere along its length.

 

[LAGlocker]

Dont know if this will help you or not, but i know on my setup I have two 1.89L bottles run into a 20 oz bottle half full of water, from which I run the tubing into the intake of a hot magnum to act as the diffuser. as far as the mixture goes, I use 1.25cups of sugar, 1t of baking soda, and 1/4t of yeast. I usually get a good two weeks out of one bottle using this, and with the two bottle setup I can change them over with out losing any run time, so it works out pretty good. get a good constant flow of co2, and at last reading I had 25ppm of co2 in my 29 gal tank I am just getting up and running good.

 

[Zezmo]

Cold can slow down your yeast production in the winter. You can put the bottle in a heated tank or bucket to keep it warm.
In my profile I have a nice yeast formula that will give you a solid 4 weeks+ of strong CO2 output. Even if you only use a basic formula, you want as much water as possible in your bottle. Add your sugar and baking soda then fill the bottle to a couple inches from the top.
I don't sterilize between batches, in fact I leave some of the "slime" from the previous batch at the bottom of the bottle. As long as the yeast gets going, it should generally out compete most bacteria. Remember, the waste product from yeast is alcohol.

 

[ringfinger]

I just mixed up some new bottles a few days ago using Zezmo's formula and I am getting amazing results. The reaction was quicker than ever, and Co2 in both my tanks is up to about 30ppm for the first time. Before, I was only able to reach a ppm of around 20. Very impressive formula. This will give me more time to be patient and save up for pressurized.

 

[Zezmo]

I am getting amazing results.

Thats awsome, I had a lot of success with that formula. In fact you might say it worked too well.
.

 

[Psychographic]

If you have a hobby store that sells gas powered radio control accesssories see if the have or can get you "fuel line bulkhead fittings" the will be for planes or boats. Slip a small o-ring (probably not necessary though) over the fitting and you are airtight! If you can't find it locally look for "Tower Hobbies" or "Stormer Hobbies" online. You should be able to get these fittings in !/8 to 3/16 inch and the should run about 3-5 bucks for a pair without shipping.

 

[youronlysin]

Good info. I've already got a bulkhead fitting on my bottle and have checked it for leaks. I am going to change to a 2 litre bottle...currently only using a 1 litre bottle and reduced recipe to compensate. That might work better, but I still dont understand why the current setup would work for a while then just quit on me. It could be that it is a bit colder there now where the bottle sits. I have new silicone airline and am going to raise the bottles off the floor closer to the tank. That will shorten the airline as well, which couldnt hurt. Either way, I think Ill completely rebuild the whole setup and go from there,