Will this CO2 running into filter work?

[Fred Dulley]

Hey guys.
Testing some things out on my 5gallon tank. It has a fluval 204 on it with tetra-ex filter inlet and outlet.
I've pushed the CO2 (DIY yeast via 2 Nutrafins) tubing just into the filter inlet so that when bubbles are produced they will travel up the pipe work towards the direction of the filter. However, none of the bubbles seem to be going into the filter. They get stuck at the 90degree bend in the pipe. Will this still be diffusing CO2 into the water? I really want this method to work because not enough pressure is build up to force through a nano ceramic diffuser (gets to a pressure where it must find a leak somewhere in the system. No idea where because it's all sealed with proper attachments, very very frustrating).
Here are some pics.

As I've been writing this post the area of CO2 bubble in the filter tubing is now quite large and is forming a large gas pocket down through the filter tubing...Don't know if it's going to stop at some point..

 

[Fred Dulley]

Right. I think the gas "bubble" has stopped advancing towards the filter.

You can see the gas coming down the filter tubing.

Gas > water

Bubbles a little further down the tubing which are coming from the big "bubble" and one by one get smaller and shoot towards the filter.

I think it's reached some sort of equilibrium and is working? Ive added a DP to check in the morning if CO2 is being diffused or not. *hopes to see green DP in the morning*.

 

[scottturnbull]

An airstone below the filter inlet might give you a fighting chance. I'm assuming the CO2 is just bubbling from a tube? The bubbles are probably too large for the filter to swallow. Large bubbles tend to float to the top. Smaller bubbles are more neutrally buoyant.

Silly question, but did you use hot water to soften the tubing when you tried attaching a diffuser? I let the tubing-end soften and push it over the collar of the diffuser to get a good seal.

Saying that, what you've got at the moment, in effect, is a bell-jar. That should work, providing it doesn't prevent the filter from working.

 

[Fred Dulley]

Yes, gas is just coming from the tubing.
Yes, did that and pushed it over the collar of the diffuser.
Ah right, well hopefully it'll work. It certainly looks like it will work now. Only bubbles less than 1mm in diameter are entering the filter. Should be ok.
Thanks.