my DIY CO2 reactor/diffuser for HOB filter

[Sar315]

I got tank with HOB filter, so inline CO2 reactor outside of tank is not possible.

I've tried different types of diffusers/reactors, they either take too much space in tank or create soda water.

Finally I tried obvious solution - reactor that uses already available water flow from outlet of HOB filter.

Design should be clear from pictures - it is a L shaped box with small hole
in a long side so that water goes but CO2 injected from below doesn't bubble through it.

Size of hole should be individually adjusted for particular filter.
If hole is too small water will overflow from top of reactor.
If hole is too big CO2 will bubble trough it.


Reactor is made from acrylic, glued with superglue and silicone.

[steven p]

I had issues with bell style diffusers, do you get a good dissolve rate or does it burp off gasses often?

I think I would want my input closer to the bottom so fine bubbles are forced to flow through more moving water.

[Sar315]

Originally Posted by steven p

I had issues with bell style diffusers, do you get a good dissolve rate or does it burp off gasses often?

I think I would want my input closer to the bottom so fine bubbles are forced to flow through more moving water.

No CO2 doesn't burp through at all. Trick is to make hole for water small enough to prevent it and big enough to go through without overflowing from top.

Yes I agree about moving input port to the bottom.
I am doing new version right now.

Another change would be to make long side of the box much narrower.
It doesn't make any sense to have it thick as it is now, it just takes space

[AirstoND]

Sweeeet!

How about putting tubing ports at the bottom instead of squared exit?

That way you disperse it via tubing to dense, planted sections of tank.

[Sar315]

Originally Posted by AirstoND

Sweeeet!

How about putting tubing ports at the bottom instead of squared exit?

That way you disperse it via tubing to dense, planted sections of tank.

I am not sure, long tube might create too much back pressure and reactor will overflow

[AirstoND]

Originally Posted by Sar315

I am not sure, long tube might create too much back pressure and reactor will overflow

Will adding a snorkel tube with one-way plastic check valve help?

[Sar315]

Originally Posted by AirstoND

Will adding a snorkel tube with one-way plastic check valve help?

Outflow of filter is only 1 inch above water level in aquarium.
Filter is open on top and there is no pressure in the system.
Anything that significantly restricts water flow in reactor will
cause it or filter to overflow.

Long tubes, check valves etc will create too much restriction.

This is the biggest problem of this system. You need to adjust water hole
in reactor to make it big enough to let water flow trough without causing overflow, but small enough to prevent CO2 from burping though it.

[mfurufuru]

Can you post as YouTube video of it in action?

[Sar315]

Originally Posted by mfurufuru

Can you post as YouTube video of it in action?

Please see new version of reactor with video here

http://www.plantedtank.net/forums/sh...46#post2818746