Very High Efficiency Reactor Design

[Chris Jackson]

Hi All,

Here's a mark one version of something inspired by Tom Barr's and Cerges reactor designs that I've come up with that I'm quite pleased with. The amount of gas burping I was getting from my existing bio ball filled reactor seemed wasteful and was bugging me and after some pondering I thought I'd give this a try. It's all made from acrylic tube and sheet and required a few tools but something similar could be made from a water bottle and bits and bobs with a bit of imagination.

It's a standard water filter housing plumbed in reverse so that the water enters centrally. I've drilled and tapped a hole so that CO2 can be input directly into the inflow. What I think the clever bit is the central tube with side holes and "perforated bubble plates" that captures water and CO2 from the inflow to maximise dwell time and agitation. My version is independently powered and features a bypass loop so that I can adjust the flow into the reactor. Too much flow and too much CO2 gets pushed straight through, to little flow and there's insufficient agitation. Having some adjustment is very useful. A video explains better...




And here's a schematic:

 

[Iain Sutherland]

i admire your engineering chris, you've clearly spent a lot of time with this. Ive built a few reactors in my time and the ones i made from acrylic look sexy and all, along with working well but less is more in this this game from my experience, especially when it comes to cleaning. Certainly having an outflow on the bottom makes a dramatic difference if your thinking about a MkII
Its tough to beat an AM1000 with no media..

 

[kirk]

Hi Chris nice idea, the exact housing Ive been looking at to build one from as you can clearly see what's going on, I wasn't planning onn going quite to those lenths in design I was going to drop a hydor korilina into it to churn the co2 up instead as I have two kicking around.

 

[Chris Jackson]

Certainly having an outflow on the bottom makes a dramatic difference if your thinking about a MkII

Interesting..I don't get how that would make any difference at all, surely water out is just water out be it top or bottom?

My thought for an improvement is for the drilled disks to be made off a more evenly perforated material than 6mm acrylic with randomly drilled 5mm holes...

Its tough to beat an AM1000 with no media..

Maybe, but fooling around with things like this is way more fun for the likes of me 😉

 

[Crossocheilus]

Looks like a great project, very well thought out, and you are getting results!

I don't really understand what the central tube is for, as it seems to be the larger tube and perforated discs that do everything. Could you not just use sponges instead of the discs? Have you got a measured flow rate which is ideal? And finally, what is and how does the venturi work?

Thanks

 

[Chris Jackson]

Looks like a great project, very well thought out, and you are getting results!

I don't really understand what the central tube is for, as it seems to be the larger tube and perforated discs that do everything. Could you not just use sponges instead of the discs? Have you got a measured flow rate which is ideal? And finally, what is and how does the venturi work?

Thanks

Ah well it's the central tube that is the really cunning bit (in my humble opinion 😉) as this redirects some of the incoming water and CO2. Because it is closed at the bottom there is a pressure build up which sends water out through the holes drilled in it between the discs to create sideways turbulence. The goal is to cause maximum agitation to the CO2 bubbles to speed up their absorption. The discs create areas for the bubbles to collect beneath whilst the central tube and side holes create more turbulence into those bubbles, sponges or bio balls seem to collect more bubbles but there is less turbulence. Previously I had a similar tube filled with bio balls and I needed twice the co2 input to get the same results. The venturi tube at the top recirculates the CO2 that collects up there for minimum wastage.

Incoming water passing by the venturi tube creates a pressure drop in that tube and this pulls CO2 up from the other end of the tube so that it goes round again (You can see it happening clearly in the video). Without that venturi there is more wastage and a tendency for CO2 to build up and up in the top of the reactor until it has to exit the "burp hole". The burp hole is also essential for releasing air when the unit is primed as well.

Ah no measured flow rate I just adjust the tap until it seems about right...

 

[Crossocheilus]

Ahh ok now it all makes sense, thanks for the great explanation. How many bps do you run with this reactor on your tank, can you compare that to an atomizer (if you ever used one)?

My thought for an improvement is for the drilled disks to be made off a more evenly perforated material than 6mm acrylic with randomly drilled 5mm holes...

Coarse sponge? That's what X3NiTH uses in his 20" version.

 

[Chris Jackson]

Ahh ok now it all makes sense, thanks for the great explanation. How many bps do you run with this reactor on your tank, can you compare that to an atomizer (if you ever used one)?

Coarse sponge? That's what X3NiTH uses in his 20" version.

Yep coarse sponge discs could work very well I'd have thought...maybe for the mark 2. (All this fiddling is partly preparation for reinvigorating my big 400 lt. tank that my daughter insists I cannot get rid of...)

With a New UP atomiser I was needing a pretty much uncountable number of bubbles but certainly in the 4 bps + range and I checked for leaks. With this, as shown in the video, it's at about 2 bps and I don't have a tank full of mist and anecdotally the fish and shrimp seem much happier without the mist as well. I hate CO2 mist in a tank, it just seems ugly and unnatural to me. At the height of my photoperiod the level of plant pearling is plenty mist enough thank you very much!

 

[Crossocheilus]

So with a lower bps, no mist and the same lighting and flow (?) You have the same plant health (or better) as with an atomizer? If so I need to think about making one of these!

 

[Chris Jackson]

Yep I'd say far better all round. I'm running higher lighting now. Aquasky 602 on for 6 hours. First 3 hours on one light at full power then 2 hours with two on full then one hour on one. Plants need trimming pretty much daily.... eeeek.

 

[Chris Jackson]

One thing to consider is that this takes a while to get up to speed on a low bubble count. You need a good build up of CO2 in there before you get maximum absorption. In my case I'm starting it at 7:30 in the morning with the CO2 climbing all morning while the plants are doing their thing in ambient light until target PH (6.3 ish) is reached for lights on at 2pm. This may not be optimum but I like the idea of gradual changes as it seems more gentle for all involved.

A swifter alternative would be to set a higher bubble rate and have the solenoid cycle it on and off every hour or so to avoid over dosing or waste.


Here's another video of it running later in the day at full chat..

 

[allan angus]

great idea thanks for sharing 🙂

 

[CJayT]

how about putting an inline diffuser into the water inlet hose instead which would give you finer bubbles which are easier to dissolve?

 

[Chris Jackson]

how about putting an inline diffuser into the water inlet hose instead which would give you finger bubbles which are easier to dissolve?

Might work but my concern would be the ultra fine / tiny bubbles making their way right through the reactor and into the tank. My desire with using a reactor is to avoid unsightly bubble mist in the tank