CO2 Spray Bar - a summary

[Zeus.]

I have only had a quick read through the thread, plus I do remember your posts elsewhere, I have to admit I am also impressed and would give a CO2 spray bar serious consideration in next tank. One less thing under the tank and seems very straight forward.

The only downside I can see is the CO2 spray bar limits ease of access to plants. Impressed with the pH drop speed also. quickest I ever had with my 500L was about 20mins for a 1.4pH drop- but that was with twin injectors reactors

 

[Koan]

Surprisingly, even though I posted earlier about the CO2 Spray Bar than the reactor, this has not gained much traction yet.

For my part @Yugang, the issue is that adding any new large distracting hardware inside the tank is a step backwards.

I'm sure the math is quite simple, but I wonder about the logistics of making these using 1/2" acrylic pipe, so that this spray bar is on the same dimensions as other Lily pipe hardware? Seems like it could be done but maybe it would require a Dremel cutting wheel, or maybe a table saw or something.

 

[Yugang]

For my part @Yugang, the issue is that adding any new large distracting hardware inside the tank is a step backwards.

That's a fair remark, and was also the main concern that people gave when posted on the other forum. I would consider it an alternative for in tank diffusers, not so much for external reactors. However, my SprayBar on a 50 gallon tank is just 10 cm long, and if I like I could also have the main part of it above the water surface so that it is hardly visible in the tank.

I am now for more than a month testing how my tank does at 15 ppm, stabilised by the CO2 Spray Bar. As for the CO2 Spray Bar in overflow mode the only concern I have found is that it does need a reasonable water flow, as stagnant water will not provide the stability of CO2 injection that we want to have. For the rest, I believe this is my setup for the next year to fully explore the pros and cons, and I couldn't be happier with how my tank is doing so far.

 

[Yugang]

It may be helpful to remember that we do not necessarily need the same design as I use, we don't need to find a transparent acrylic tube or do the DYI. The only essential part of the design is a constant surface area between water and CO2, and an overflow for the CO2. Besides that, we are almost unrestricted in the design of the Spray Bar.

Take the little box that is part of the 17 piece IKEA Pruta food container set, and it will work as well. IKEA sells the full set for about 5 USD.



I currently use 3.500 mm2 to push about 10-15 ppm on my 50 gallon tank. I use the design on he left in the picture.
The small IKEA box on the right measures 80*80 = 6.400 mm2, and could be made into an overflow CO2 Spray Bar by just mounting it upside down in the tank, with a CO2 tube leading to it. The only modification needed would be to cut or drill a small hole in the side, so that bubbles can escape for overflow mode and keep the surface area constant. When the box is above the water, only the walls just below the water line even less visible.

 

[Art]

So @Yugang this seems to be a similar concept to the old CO2 bells that we had that allowed for a gas bubble "burp" to clear out when too much gas. Your design is more streamlined and explains why/how it works. Correct?

 

[Yugang]

So @Yugang this seems to be a similar concept to the old CO2 bells that we had that allowed for a gas bubble "burp" to clear out when too much gas. Your design is more streamlined and explains why/how it works. Correct?

The benefit of CO2 Spray Bar is that it keeps CO2 stable with overflow mode, and is continuously refilled. The similarity with CO2 bells is that it uses a flat water/CO2 interface rather than bubbles. I am not a fan of the old bells because they were not stable - this is probably why they have nearly been forgotten and diffusers and bubble reactors became the standard.

 

[*Ci*]

I am working on a couple of co2 sparybars for my two tanks, and have a question, @Yugang
I want to mount them above and slightly in front of my water return spraybars as you have done, from these pictures on your old UKAPS thread:



How did you mount it? Suction cups won’t work in this position.

I guess your UKAPS thread was taken down at one point? It is there again now, in case you did not know:

CO2 Spray Bar

 

[Yugang]

I am working on a couple of co2 sparybars for my two tanks, and have a question, @Yugang

Always happy to help @*Ci* , nice that you give it a try. Let's keep in touch on PM as well, if the below is not clear enough.

How did you mount it? Suction cups won’t work in this position.

I drilled holes in the end caps, and used a screw to connect the caps of water spray bar and CO2 Spray Bar. In the photo on the left, looking through the hole for overflow, if you look carefully you can see the screw as well.
There is no need to connect the CO2 Spray Bar to the water spray bar, I currently also don't do that, but it is really important that the water under the CO2 Spray Bar has some flow. With nearly stagnant water the CO2 Spray Bar still works, but the absorption will be limited by diffusion in the stagnant water and be less predictable.

I guess your UKAPS thread was taken down at one point? It is there again now, in case you did not know:

I wasn't aware, and this is really good news. I have asked them to remove the end posts from the mods regarding the ban, as these were written long time ago when facts and emotions had gotten a little bit mixed up.
Perhaps a revitalised UKAPS will even reevaluate the bans of some former members and welcome also their former admin again.

 

[*Ci*]

I drilled holes in the end caps, and used a screw to connect the caps of water spray bar and CO2 Spray Bar. In the photo on the left, looking through the hole for overflow, if you look carefully you can see the screw as well.
There is no need to connect the CO2 Spray Bar to the water spray bar, I currently also don't do that, but it is really important that the water under the spray bar has some flow.

Yes, I see it now. Since my Co2 bars will be shorter than my water return bars, I think it might be best to position them in the middle of each tank. Both tanks run 2 canister filters each, so I have double spray bars, one on top of the other across the backs of the tanks. I’ll try zip-tying the Co2 bar to the upper water return bar, and maybe direct some of the lower water bar flow towards it.

This is after I get them built, and then I have to sort out malfunctioning co2 regulators as well, But I will update when everything comes together!
Thanks for your help : )