Thank you for your questions and observations
@LMuhlen @LondonDragon @LightingBamboozled , let me try and clarify.
The reactor is just a pipe with a water flow, with a CO2 pocket above. It is a plumbing PVC pipe, with glued or screwed end pieces.
it does seem a little noisy
With a large enough pipe diameter, and a gentle flow there is no way there would be any noise. It is just a gentle stream of water. A bigger flow will create splashing and CO2 bubbles making noise, while it will not benefit the aborption and working of the reactor.
a bypass has made it significantly quieter
@Unexpected initially started with a powerful pump, later corrected this to a smaller pump and a bypass. I would generally recommend a bypass, as the reactor works best with gentle flow and the bypass will still make full use of the pump capacity for circulation in the tank.
Will you need a dedicated pump for this or could be place in the filter output?
Just on the existing pump, and if that is too strong use a bypass.
I guess the only pain as with any other reactor would be to take it all apart to clean it on a regular basis as with all your filter pipes
I clean filter pipes to improve flow from my pump, but see no reason why I would clean the reactor. In fact the opposite,
fill it with bioballs to create a biological filtration Even if you still like cleaning the reactor, it can't be that difficult to clean the inside of a 1 m tube?
The trick would always be to get them level, some tube clamps at the back of the cabinet should work.
There is really no reason, see picture above, why this should be very precisely levelled. If the pipe diameter is big enough there is no problem if you tilt it from its horizontal as long as the CO2 does not escape from the exit.
Would be good if any UK based member had the skills to make some of these and some could test them, off course pay for materials and labour costs to make it worthwhile.
The principle is so simplistic that I really can't see what could go wrong. There are probably hundreds of threads on fora how to make bubble reactors work (vortex, single or double venturi, needle wheels, impellers, diffusers, noise, double stage), but we can consider that a problem of the past IMHO. Visit the plumbing shop, buy a pipe, end pieces and glue, follow the design rules from this thread and job done.
I am not great at putting this kind of stuff together (as most will not be either)
A plumbing pipe with two end pieces? Where do you see the challenges putting that together? You got your advanced CO2 controller and 3D printer to work, now politely suggest to roll your sleeves up, cut some tube and glue the pieces together as we used to do in the good old days
would be afraid of leaks, but then again I am running a cheap Chinese made one under my tank, (which works just fine, and I do have a leak alarm that triggers an alert on the phone, might not help depends on where I am lol).
A 'cheap Chinese made" with a leak alarm safer than a PVC pipe with 2 end pieces glued, or screwed?
I would keep it outgassing a bit. I worry that long term you would have some dilution of your CO2 atmosphere with gases escaping the water into the reactor. When you constantly outgas this atmosphere, you keep it at a steady condition of lower dilution of the gas. The original setup with the open reactor inside the tank would renew the atmosphere with every water change.
It is what I originally thought as well, but from experience I learned it is not really necessary to have a purging valve. I described the self purging in the thread
CO2 Spray Bar and same applies to horizontal reactor. When the gas bubble still contains a mix of air and CO2 the absorption efficiency will be lowered, the gas pocket will grow and the reactor will start to self purge bubbles through the exit. This will clean out the air in the gas pocket, and soon I found that only CO2 remains and the reactor has purged itself.
@Unexpected (against my advice, but he got it right) did not design in a purge valve, and he is successful with it.
But had similar concern that 1200 lph filter may be too fast for it.
Depends on the tube diameter, but easiest would be to use a bypass if the pump is too strong for a gentle flow inside the reactor.
Also, does it matter which end of the reactor the CO2 is injected in?
I would prefer as far as possible from the water outflow, just to be sure the bubbles end up in the gas pocket and are not blown straight out of the reactor. This again is less critical if the flow is gentle.
(sticking a diffuser in bleach for a few hours is so much easier, or have two and alternate)
From physics perspective diffusers are suboptimal. Money can be earned with it so probably the tradition will be kept alive for a while, but I expect that small horizontal reactors will be adopted for smaller tanks and replace diffusers.
So what is the problem with diffusers? First, they create mist in the tank. Then bubbles escape to the surface, so no matter how precise your regulator is you will never know how much CO2 actually absorbed into the water and thus have a challenge achieving CO2 stability. Diffusers age, and in between maintenance the bubble patterns gets less fine, so their performance and CO2 stability is not constant. Diffusors also have limited capacity, so can not be used on larger tanks. The horizontal reactor has none of these issues, in fact I have yet to discover any disadvantages.
