|Yesterday 07:21 AM|
CO2 reactor -packed column
The concept is similar to my build of a large scale bubble column prototype. In that design I discovered that an internal venturi is highly effective at dissolving Co2 into the water. With this packed column we can get the highest efficiency in a small package. The principle of efficiency is simply due to surface area - the media forms a huge surface area for gas-liquid contact. Excess CO2 is collected in the top of the tower and is recycled by the venturi. When CO2 is consumed the water level rises and more gas is allowed to be injected. In case of confusion I would like to clarify this is not a pressurized setup.
Here's how it works:
CO2 is injected through a T junction in the incoming water. An internal venturi/nozzle sprays water over a packed bed. The ideal packing is pond filter media pictured below. This allows a thin film of water to flow down and contact the CO2 gas over a large surface area. A layer of water on the bottom allows any entrained bubbles to float up, and clear water exits to the tank.
A side mounted water level float switch is crucial to the design. These can be picked up on a Ebay for around $10. This switch is triggered when the water level rises and energizes the CO2 relay allowing more gas to flow in. The gas pressure keeps the water level down and prevents the packed column from getting flooded.if the column is flooded then the gas-liquid surface area is reduced. That's why packing media in a conventional Cerges or Rex Griggs is usually of no benefit.
The column should be around 4"dia and 12-18"in length for 200-400 gallon tanks. Flow rate can be very slow (about 100 gpm) so you only need to divert part of the flow from a canister and not compromise the performance of your filtration system. Smaller designs can be made for smaller tanks (ie. a 3" x 12" reactor for a 100 gal tank)
Gas flow rate for my bubble column setup is about 2-3 bps for a 200 gal set up so I think that this should be similar or better in terms of CO2 consumption.
Since this reactor is self regulating there is no need for a bubble counter and a precision valve and regulator. This saves a lot of $$$ and headache in fine tuning your CO2 system. A lower cost single stage regulator will do fine. The amount of CO2 delivered to the tank will actually depend on the flow rate of water through the reactor. The faster the flow the more CO2 will be dissolved out and flow to the tank.
Made from 4" PVC pipe, I would use clear PVC on the center section, the caps can be white PVC. For easy cleaning I would suggest using 4"dia threaded PVC fittings. Float switch can are be installed with a small hole drilled on side and an O ring+ silicone sealant. Some valves come with bulkhead fittings that provide a better seal. Total parts are about $75.
If anyone is interested in building one please let me know and I can help you get the parts together.
|04-16-2014 01:04 PM|
If I really don't have the time to build my own reactor, and if I did the water filter housing I was looking at is almost $90 as I wanted the large 20" one, would I just be better off to go with CarbonDoser EXT5000 (External Reactor 5000)? It going to run on 180 gallon system with 75 gallon sump, will also be setup using it own pump.
|04-13-2014 02:37 AM|
|kevinmichael77||No parts yet. Still wasn't sure if it's worth it or if I could build it.|
|04-12-2014 10:28 PM|
|04-12-2014 10:26 PM|
Did it inhibit the flow at all? Only thing is I'm not handy at all so not sure I can put it together properly
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|04-12-2014 10:20 PM|
|04-12-2014 09:48 PM|
So would I need a powerhead of I decided to use one of these or can I just run it off my eheim 2217 canister filter? My tank is a 33 gal, right now I'm just using a atomizer but the tank gets a lot of co2 bubbles.
|03-24-2014 01:44 AM|
|03-24-2014 01:42 AM|
|03-16-2014 10:28 PM|
My Ista Max Mix started leaking. (I haven't touched it, the attachments just decided to leak). So I have been looking into something that is of better quality.
|03-15-2014 01:43 AM|
Well i threw one of these on my tank just to see the out come an i guess its pretty cool. Over the past month my tank started getting worse with CO2 looking like "soda" in a cup, anyway i had a couple filters for a few months now an wanted to see how it goes diffushion an rha whole nine. So far so good the only difference i dint have which a few others had was lowering of the bubble count / output, its only been a day an it took 6hrs for my drop checkers to change a little bit. Thats already telling me that my CO2 either aint high enough or im loosing some along the lines somewhere. With my regular ceramic diffuser it only takes a few hrs i should have timed this to see HRS exact but i do know that by the time of shut down drop checkers are a light lime green almost yello an they stay like that till sometime between 12am-5:30am. My co2 comes on at about 7:30-8:00am lights come on at 9:00am an off at 7:30-8:00pm lights off about 9:00pm. Well on to my thrown together set up,
Another thing i liked was the plants pearling a lot which told me they were using CO2 at the time they were supposed to. Drawback to this setup is how it fills to the top with water, i feel like its gonna start leaking one night or day an my aquarium is right abouve me n my wifes bedroom so u can see how this would be bad. Also the fact that my house will be flooded from all 70gals from my tank, im gonna tighten everything up later today with all pvc parts or better looken ones anyway.
|03-10-2014 10:39 PM|
|03-10-2014 10:24 PM|
I'll keep looking for PVC components. This is what I've ended up with so far...
|03-10-2014 04:32 AM|
|03-09-2014 10:36 PM|
The primary concern is invert and fish toxicity.If you keep doing regular water changes its fine.
You can find virtually any brass pipe fitting in plastic form (HDPE or PVC) online.
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