co2 diffuser problems

[genitor]

Below is a diagram of the co2 diffuser I made.


1753

The problem is that as the pressure builds up inside the bottle top the red line drops lower and lower until a big bubble explodes from underneath it. How to i stop this from happening?

[RobbieG]

That looks to be a combination of two different diffusers.

If I understand you correctly ... You use the airstone to get little bubbles - but inside the bottle top they just form a big bubble and plop out.

If you have a canister filter you can run the output line from the 2 liter bottle into the intake for the filter (this is supposed to give the CO2 plenty of time to dissolve into the water.

If not I would try using just the airstone with no bell

I've tried just the bell and it does the same thing - Just the bell with current running past = it same thing

Just the bell with hole in it = same thing

I am going to try the airstone thing myself this weekend.

[Chrona]

You have no movement in the bell. Most reactors built like that use a powerhead to swirl up the water inside the bell to speed up CO2 diffusion. If it's still in there, the CO2 can't diffuse fast enough to keep from spilling out. Either get some current under that, or a finer diffuser + put the bell (not the diffuser) higher up so the bubbles travel through the water longer.

[RobbieG]

You have no movement in the bell. Most reactors built like that use a powerhead to swirl up the water inside the bell to speed up CO2 diffusion. If it's still in there, the CO2 can't diffuse fast enough to keep from spilling out. Either get some current under that, or a finer diffuser + put the bell (not the diffuser) higher up so the bubbles travel through the water longer.

That makes sense - I was running the current under my bell not into it

[genitor]

Ok, I moved my airstone right down to the bottom and moved the bell upwards to about 4 inches from the bottom. I also put a pinhole in the bell closer to the base than the top so that if the pressure in the bell builds up and the water line reaches the hole some pressure will escape and prevent the "explosion". I don't have a powerhead so I can't incorporate one into the design. Don't have a canister filter either. Thanks for the info everyone.

[RobbieG]

I put a bunch of pin hole in my bells for some reason the CO2 seems to just like to belch out from around the side. I'm going to pick up a couple of airstones tonight.

I've got 2 setups so I'll try a couple of different things and post what works best. (I'll hold off on the powerhead as you don't have one)

If the setup you are trying works could you let me know?

[Drumachine09]

I put a bunch of pin hole in my bells for some reason the CO2 seems to just like to belch out from around the side. I'm going to pick up a couple of airstones tonight.

I've got 2 setups so I'll try a couple of different things and post what works best. (I'll hold off on the powerhead as you don't have one)

If the setup you are trying works could you let me know?



Couldnt you just run the tube up to the intake of the powerhead if you had one?

[genitor]

I put a bunch of pin hole in my bells for some reason the CO2 seems to just like to belch out from around the side. I'm going to pick up a couple of airstones tonight.

I've got 2 setups so I'll try a couple of different things and post what works best. (I'll hold off on the powerhead as you don't have one)

If the setup you are trying works could you let me know?


The setup works, I used one pinhole. The water level in the bell stays at a constant level and if the pressure builds up too much a single bubble escapes from the pinhole. So no more belching. Wish i had a pic but i don't own a camera. Let me know what you came up with.

[marcryan11]

I agree. We had a ghost knife that thought the diffuser was a toy and broke it, so now we direct inject to the outlet as far from the spray bar as we can. actually diffuses quite well. Also when we did that, the plants in the tank started to boom again.

[RobbieG]

The setup works, I used one pinhole. The water level in the bell stays at a constant level and if the pressure builds up too much a single bubble escapes from the pinhole. So no more belching. Wish i had a pic but i don't own a camera. Let me know what you came up with.


I must have made the holes too small

[genitor]

I doubt your holes were too small. Move the airstone/hose down and move the bell up so that the co2 has more time to dissolve before it reaches the bell.

[Chrona]

Without a strong current in the bell, you won't be dissolving much CO2 from it, so I think you'll probably be better off getting a glass diffuser (or even just the airstone you have now) for like 10 bucks and sticking it under the output of whatever filter you have so it blows the bubbles back downwards again and around the tank a little (very unnoticable - what I have set up). The flow of microbubbles from a glass diffuser is also very beneficial to the plants.

[genitor]

What's a glass diffuser?

[Chrona]

How big is the tank?

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[dev]

What's a glass diffuser?

It's a glass device with an inlet and microscopic holes that give out tiny bubbles that almost looks like smoke in water.

[genitor]

[QUOTE=Chrona]How big is the tank?

Tank is 15 gal.

I've never seen a glass diffuser in any of my lfs. Looks really cool though, I would like to get one.

[dev]

I've never seen a glass diffuser in any of my lfs. Looks really cool though, I would like to get one.

If they carry any CO2 equipment they may have some tucked away somehwere, they are usually quite small.

[RobbieG]

I am trying Chrona's set up with the CO2 coming out under my flow.

I ran out of couplings and it was either that or trying the airstone right inside the bell.

I had to get more sugar for my soda bottle's and recharge - I wans't getting anywhere near enough pressure to blow bubbles :(

Right now I have pearling in both tanks just hanging my airstones under my HOB :)

Found a bunch of other ideas too!

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