Diy yugang/bell diffuser test.

[snowballs99]

10 gallon tank.
3 inch diameter water bottle.
JUst needed something quick and easy for farm tank. If this works can easily scale up to a 1 gallon water bottle for a 20 long.

Around 7.1 sq contact area calculated on chatgbt.

Hoping for around a 0.7-1.0 ph drop over 3-4 hours. A small internal filter directed at it for flow.

 

[Koan]

@Schrute66 also experimented with a pretty cool Yugang bell diffuser here

Journal Post in thread 'Plenty of Tech 15g AIO Cube'

Oct 20, 2025

DIY CO2 spray bar/open flow reactor
Here's how I integrated the CO2 spray bar idea into my small AIO aquarium. You can see here that all the flow through the AIO system comes up through chamber two and spills into chamber three where it's returned to the tank. This seemed like the best spot to position the reactor if I could find a small vessel that would work. There's only about 3" by 3" to work with. The surface area of my tank is about 210 sq. in (14.5" x 14.5"). The rough math as I understand it for a 1.2 pH drop would require a little over 6 square inches of reactor surface...

• Schrute66

• 
• 

His wasn't ultimately successful due to purging issues

 

[Pepere]

I use three of these glass bells with suction cups to attach to glass face in a 20 high.



Small 3 watt 80 gph powerhead underneath.

Gets me to about 15ppm co2

 

[snowballs99]

@Schrute66 also experimented with a pretty cool Yugang bell diffuser here

View attachment 16706

Journal Post in thread 'Plenty of Tech 15g AIO Cube'

Oct 20, 2025

DIY CO2 spray bar/open flow reactor
Here's how I integrated the CO2 spray bar idea into my small AIO aquarium. You can see here that all the flow through the AIO system comes up through chamber two and spills into chamber three where it's returned to the tank. This seemed like the best spot to position the reactor if I could find a small vessel that would work. There's only about 3" by 3" to work with. The surface area of my tank is about 210 sq. in (14.5" x 14.5"). The rough math as I understand it for a 1.2 pH drop would require a little over 6 square inches of reactor surface...

• Schrute66

• 
• 

His wasn't ultimately successful due to purging issues

Surprised he got a 1.0 ph drop with such a small surface area.

I didn't notice how easy CO2 in these bells actually dissolve into water. I need a 1.5 bubbles per second to keep the bubble pocket steady and a purge every half hour.

 

[snowballs99]

I use three of these glass bells with suction cups to attach to glass face in a 20 high.

View attachment 16707

Small 3 watt 80 gph powerhead underneath.

Gets me to about 15ppm co2

Could u perhaps place 3 more on top of those to catch the purged CO2 overflow? Lol.

 

[Pepere]

Could u perhaps place 3 more on top of those to catch the purged CO2 overflow? Lol.

If I did, the co2 level would increase.

I am feeding these bells with soda bottle sugar fermenters.

I have three hooked up to a manifold. I swap the oldest one of the three every other week.

1 cuo of sugar, and 3 packets of great value gelatin.

 

[snowballs99]

UPDATE:

At first I was only getting like a 0.6 ph drop, and I kept wondering why. The co2 gas pocket also wasn't dissolving nearly as fast as my other 5.5 gallon tank, which was getting double the Bubbles per second.

Then I realized that I didn't purge the oxygen in the bottle out when I initially put it in the tank. I purged all the oxygen out by unscrewing the cap and filled it up with pure co2.

Then magic, 1.3 ph drop in 2-3 hours. From 7.5 ph to 6.3-6.2, works almost a little TOO well.

Will have to downsize it a bit after my slightly better looking bell diffuser arrives.

So I can say with certainty, if you need a really shitty looking co2 diffuser made with a water bottle, scissors, and some rocks, I don't think you're going to find anything that out performs this.

If you aren't sure how its made, it's literally just a soda bottle, with 4 large square holes in the center for water flow. Fill the bottom of the soda bottle with some rocks to weigh it down, and stick an airline with co2 in the center of it so the bubbles collect in the top portion. Remember to unscrew the cap first and purge all excess oxygen out of the bottle. You want just pure co2 in there. Pure Co2 dissolves VERY easily and fast into water.