Dual venturi DIY External CO2 reactor

[Tom Barr]

I watch the plants, if strong pearling is evident, do not worry, after about 1-4 hours in to the light cycle, if you have good pearling, that's about right and what you want to see.

At lower light, maybe the last 2-4 hours will pearl, even in my non CO2 tanks, I have good pearling.

Regards,
Tom Barr

[rubb]

Thank you Tom about such an simple but effective design

I have 2 questions:

1. what is minimum GPH of filter pump for this reactor to effectively work? I have ~50G tank with JBL Cristal Profi 250 external filter ( around 100GPH ).
2. I hear people that they hear noises coming from reactor... is it really noisy? May be noise is only when CO2 is being injected, or noise is from water flow? My aquarium is in bedroom, so it is important for aquarium stuff to work quiet.

[mrkookm]

The outlet is stuck right into the sponge for the 1800 gph return to tank, so I think the c02 is well chopped and distributed!

Am still playing with c02 rates as my drop checker is still blue

Your problem with the DC remaining blue is due to too high a flowrate, reduce this by more than half for best results. I have a 1900GPH pump and I reduce mine to 500~600GPH and my DC is limegreen anything higher and my DC will be blue even though lots of mist will be in the tank.

I hear people that they hear noises coming from reactor... is it really noisy? May be noise is only when CO2 is being injected, or noise is from water flow? My aquarium is in bedroom, so it is important for aquarium stuff to work quiet.

Noisy....well if you put your ear directly on the PVC you will hear the churning on the inside but I would'nt classify this as being noisy. This isn't audible standing back or mounted normally, well at least not IME and I truly doubt a canister filter will provide the flow required to produce this 'noise' you heard about anyways.

I am using an external 300GPH pump to power my reactor. Since it's only powering my reactor I have barely any head-loss as opposed to a canister with all the extra media therefore I am pumping more water @ a higher pressure causing more intense churning and I don't hear anything so If there was noise I would have certainly have heard it because of my setup. I am very sure you will not hear any such noise with yours...it's an excellent reactor that gives great results....try it

[Gerryd]

Hi,

Thanks for the reply, but.....


I am only using a 500 gph to run the reactor. The 1800 gph is for the ENTIRE tank. The outlet FROM the reactor goes into the 1800 and back to tank.

I am a little confused by your answer as others here had recommended the increase from what I had.....

When you talk about reducing flow rate, which flow rate do you mean?

Remember that my tank is 180 gal, so reducing the pump outflow by 50-60% will have a detrimental affect on my tank..........


Appreciate the help.

[mrkookm]

Hi,

Thanks for the reply, but.....


I am only using a 500 gph to run the reactor. The 1800 gph is for the ENTIRE tank. The outlet FROM the reactor goes into the 1800 and back to tank.

I am a little confused by your answer as others here had recommended the increase from what I had.....

When you talk about reducing flow rate, which flow rate do you mean?

Remember that my tank is 180 gal, so reducing the pump outflow by 50-60% will have a detrimental affect on my tank..........


Appreciate the help.

I know the 1800GPH is for the entire tank but that is way too much flow and half of that amount would be a step in the right direction while still maintaining a 5 x turnover rate. Correct me someone if I am wrong here but I also think contact time with mist is also important. IME when I turn up my flow the mist in my tank move all about so quickly with zero contact time and it's a waste, I reduce my flow and voila! My plants pearl like crazy and my DC changes color in no time. If you are going to continue using that much flow you would be better off using a mazzei injector, at that flow rate the force water going through the injector should diffuse the co2 rapidly and raising the Co2 needed at that flow quickly.

What kind of tank do you have that requires this much flow is it mostly big fish or is it planted? I know of others who has bigger than you and use less flow, you do not need 1800GPH on a freshwater tank unless you have a couple stingrays and sharks?

Maybe TBarr can chime in more on this issue? I'm also a little curious of the turnover flowrate that is used

[Tom Barr]

Thank you Tom about such an simple but effective design

I have 2 questions:

1. what is minimum GPH of filter pump for this reactor to effectively work? I have ~50G tank with JBL Cristal Profi 250 external filter ( around 100GPH ).
2. I hear people that they hear noises coming from reactor... is it really noisy? May be noise is only when CO2 is being injected, or noise is from water flow? My aquarium is in bedroom, so it is important for aquarium stuff to work quiet.

1.I'd run 200gph or so
2. No, not much. Work on making the inside of the stand quiet also(padding, insultation materials, rubber etc).

Regards,
Tom Barr

[Tom Barr]

I'll be using 1600gph or so on my planted tank that's a 180 gal.

I can always reduce flow with a ball valve.

The wet/dry will run about 800gph.
Canister will run about 800gph.

Heater is in the sump, and the CO2.

UV in the canister loop and the Tee for back washing the filter/draining it, and for the tank drain.

Backing off the flow suddenly will always show pearling.
O2 can accumulate and diffusion is slower with less flow, does not imply that there is less/more growth however over time.

You would need a total O2 production curve over an entire day to see the differences.

But if you get good pearling and like the slower flow, and it gets the job done, then that's what I'd suggest sticking with.

That is what you want and you can see that, better than any test kit or ppm's reading. Flow can blow that off while still producing higher growth rates, thus you cannot tell as easily.

More growth is not always better, but I think a good visual cue it more important as long as algae and good over all tank health is good.

Regards,
Tom Barr

[mrkookm]

That is what you want and you can see that, better than any test kit or ppm's reading. Flow can blow that off while still producing higher growth rates, thus you cannot tell as easily.

More growth is not always better, but I think a good visual cue it more important as long as algae and good over all tank health is good.

So as long as their is lots of mist all about even though visual pearling is not seen until flow slows and DC remains blue, Co2 levels can be assumed good?

[Gerryd]

Hey mrkookm,

1. Remember that my head height is close to 5' so, only 1200 gph at that level

I used to have two 500 gph pumps, but Tom had suggested going higher. I chose the 1800 gph as it was not much more $ than the 1200, and with the ball valve I knew I could reduce if necessary......

2. I do get good pearling within 1-2 hours of lights on and it is very obvious, so the DC color is not as important to me, as the other visual clues as per Tom's earlier response. Tank is very healthy.......

3. My fish DEFINITELY like the higher current. They spend most of the day swimming against it in large schools, which I like

4. Planted community tank with several hundred small tetras, corys, dwarf cichlids. No big fish, rays, or sharks .

I am now curious about the reduced flow and will try it later for a few minutes and see if there is a difference in pearling..........

thanks for your replies

[Tom Barr]

I think it's a huge myth fish do not like higher currents.

They get fat, lazy, just like us.
They do not look as nice, they do not behave like they should, they do not eat nor grow as well either.

Like us after exercise, we are alive and hungry.
Some use powerheads for 2-4 hours a day/at night etc to exercise their fish.

They want rest, they can wondering into the plant beds.

Regards,
Tom Barr