CO2 rector with just a power head and lots of airline

Hello everybody,

I think I found an inexpensive (as in really cheap) way to dissolve CO2 in a tank. It's so simple, it's probably been done before and the old timers in here will probably point out that they were doing it this way years ago. It's kind of a mix between a venturi and a good old ladder.

With time, I came to realize that CO2 is easy to dissolve in water. If the gas remains in contact with flowing water for long enough, it will dissolve.

All you need is the following:

1. A powerhead (with venturi input)
2. A standard T
3. Lots of airline (I'm testing it with just 6 feet, it's what I have laying around... more could be better)
4. A small piece of foam/sponge (like the sponge inserts in filters)

Here's a crappy plan, I have not included the checkvalves:



Some CO2 still makes it to the powerhead, but compared with the gas that is sent in the system, it's not that much. I think that if I use 10-15 feet of hose between the powerhead and the T connector, more gas could get dissolved, not certain yet...

Any thoughts?

Cheers!

 

Indeed, but I'm really rubbish at making and watertight vessel... I tried to make an external reactor like the ones Redsea sells.... The reactor worked really well, but there were leaks. I really do not trust my craftsmanship when it comes to water. I'm certain that my landlord downstairs will appreciate it.

Probably, you really like those eductors Biollante don't you. The thing is, I read that they are rather noisy and I like my tank to be silent. The bonus is that since the "leftover" gas does not pass through the imperller, I don't get the chopping noise. Are eductors really as noisy as some people claim?

It's only been 24 hours since I set it up and as of now, the CO2 levels look really good. I may even adhere to the "church of use a solenoid". Oh yeah and that ugly Hagen ladder will be history.

I'll try to add a longer airline and an eductor sometime this week to see what happens.

Thanks for the comments Biolante.

 

Hi everybody,

Thanks for all the posts.

Eductors are not as noisy as I thought it seems. The one video that I saw that had decent sound (and not some boom boom music) was of a marine tank. I think the eductor was left to the open air and not connected to a CO2 cylinder. The sound I heard must have been from the outside air rushing in.


Update on diffuser:

I works. More or less. It's far from being perfect though... I was able to get maybe 75-80% dissolution of the gas, there seems to be a point where adding additional tubing does not help much. The gas just stops dissolving. Perhaps the water in the tubing becomes too saturated to readily dissolve more gas.

Also, as one adds more tubing, one also need a more powerful powerhead/pump. If I add too much gas from the regulator, the powerhead and the long section of tubing become "air jammed". The gas just exits from the sponge where there is now less resistance (since the pumps no longer does it's job). You also have to prime the tubing. I don't mind an occasional swig of tank water, but I try to avoid it.

The conclusion is that it can work. If someone wants to add CO2 on the cheap. It is by no means perfect and it will not dissolve 100% of the gas, but since a lot of us already have powerheads, tubing and a T laying around somewhere, it can do the job.

I have finally opted for a DIY internal reactor based on Tom's plans except on mine, I made it so that the powerhead stays horizontal and so does it's output (I wanted to use the suction cups of the powerhead and to use it to create additional circulation). It works well, dissolution of the gas is not 100%, but gas is relatively cheap... The way I setup my DIY reactor also creates a misting effect, so that's a bonus right there.


I think it will do nicely until I get my hands on an eductor. I could try to get one for free... Hummm...

Biollante, send me an eductor asap or I'll send Godzilla over to your place. Now you remember what happened to you last time you two met right?

/ I know, it won't work... Biollante is not scared of the threaths uttered by a mere human
// And I lost Godzilla's phone number...