DIY CO2: too many bubbles?

[skylsdale]

I just decided to slap together a DIY CO2 rector for my tank, which I haven't done in a couple years. I'm using a Tree Top apple juice container, I would assume it's about a gallon or so. I've put it all together and added the recipe. The airline (with check valve) is connected to the intake of a Duetto submersible filter (which I used last time as well).

However, it is spitting out tons of bubbles, and has been for the last half hour since I connected the airline. I don't remember this happening last time. Is it just suckingout all the O2 in the chamber...or did I botch something up? I've already run a search on this, but can't find an answer to my question.

[BobbyDrake]

What mixture did you use?
How full is the container?
Are you using a bubble counter? (doesn't really matter, just curious)

What rate is it putting out the bubbles, 20-30 per minute or even more?

[skylsdale]

I used:

2 cups sugar
2 cups water
1/4 tsp yeast

I mixed the yeast with 1/4 cup of tepid water, then dumped it in with the sugar and the remaining 1 3/4 cups of tepid water. Fluid depth in container is 2". Not using a bubble counter, and there are too many coming out to count. It's a steady stream, as if air is seeping into the filter. I checked the lines, and I don't see where air could be entering.

Is it possible that it's just producing so much CO2 initially that it's literally just pouring out like this?

[ninoboy]

I think there is a leak in your sistem. I am also still playing around and experimenting with different bottles, mixtures and connectors. I found out that there are many spots those could leak. I even had a leak on my T connector (poor quality ; the end not really rounded and leak air overtime). I also had problems with different bottles. The caps of some drinking water bottle actually are not air tight. But it really looks air tight and even pass the "submerge under warm water test".

Why don't you take out the output from the intake and just let it sit in the tank. This way you can count the bubble.

[skylsdale]

I think you're right on the leak. Woke up this morning and the same amount of air is just streaming out of the filter. I'll have to scrounge up a 2 liter bottom somewhere--that's what I used last time and it was nice and air tight (I'm sure pop bottles are designed to minimize leak to help keep the liquid carbonated).

[malkore]

if you have a steady stream of bubbles, how could there be a leak? Sounds like your yeast solution is just going like mad...yes...it can do that...especially if hte temperature in the room is warmer than 75 degrees.

[skylsdale]

Well, I made a container out of a 2 liter pop bottle today and just hooked it up. Yet again, another steady stream...only this time the walls of the container and being pulled in. Here's a pic:



Any ideas? I assume that if the walls of the container are imploding, then not enough CO2 is being produced.

Room temp runs between 70-74*F.

[BobbyDrake]

How exactly is it attached to that filter? By the looks of things, you may be suckign the air right out of your pop bottles. There really shouldnt' be any suction directly on the airline hose, just enough to pull the bubbles in once they are released from the tubing.

[skylsdale]

It's attached to a venturi intake on the filter. I did this last time and had no problems whatsoever. I don't understand why it would be creating so much pressure this time and I didn't experience this last time.

Also, when I disconnect the tubing and let it sit beneath the water level...nothing comes out. Actually, water slowly rises into the tube to meet the water level. Would this be any indication that there is no CO2 production going on?

[ninoboy]

The water in the tube should start at the water level and then slowly move downward as the pressure inside the canister build up. If nothing happen in 20-30minutes and you mixture is active, there is a leak somewhere. It doesn't mean that your mixture doesn't produce CO2, it just doesn't create enough pressure because of the leak. To check whether your mixture is working, you can use a flashlight pointing to the surface. You should be able to see a lot of micro bubbles moving to the surface. They are extremely small and look more like white dust moving up.

I read a question that someone posted at the Hagen website. He was asking whether it is safe to connect the DIY CO2 output to the venturi. The technician said that there is no definite answer. The design of powerhead did not take into account that function. He said it all depend on how powerful the powerhead is. If it's too powerful, the suction on the venturi can collapse the bottle.

Why don't you just stick the output tube to the filter intake. It'll have much less suction there.

Also, try to apply some silicone sealer to all connector to make sure there is no leak there (it happened to me twice, once at the T-con. and other at the tube connector). Those silicone is easy to peel if you want to disconnect it one day.

It took me all night long to figure out those leaks (and another all nighter the following week), so don't give up yet.

[skylsdale]

I think I'm going to go pickup some silicone sealant today. I used this last time where the tube inserts into the bottle cap...but didnt have any on hand this time. I thought the seal was tight enough, but I'm thinking now that it's not.

[malkore]

Yeah, the setup you have there is definitely trying to create some suction on the CO2 line. I have a similar filter, and honestly it's not gonna be the best CO2 diffuser. You might have more luck though attaching near the intake area. There it can get slowed down by the filter media...staying in contact longer with the water...which is where it diffuses.

I think, however, you'd see the best results by getting a Hagen/Nutrafin diffuser (I know www.drsfostersmith.com sells just the CO2 diffuser/ladder), and use it instead. you can put it by the filter, so it's pushing the CO2 rich water around the diffuser all over the tank.

[Bronx19]

I too had problems with leaks. I had to put silicone on the thread of the bottle cap and then do it up. No more leaks.

[sirfishmaster]

i also use a Duetto submersible filter and works great, i melted a hole just above the grate for the intake, and stuck the tube there, then i took some plastic shot glasses and squeezed them in the container, this holds the c02 longer in ech compartment.....works great, although a lot of slime build up after a while


doug

[Fat Guy]

Why are you mixing only 2 cups of water with 2 cups sugar and 1/4 tsp yeast?

2 cups water?
Why so little?