I have an old "vertical" CO2 reactor lying around (next to my UNS 90B, an upcoming project!):
This old reactor works by making a "vortex/spiral" of water flowing in due to a 90-degree elbow piece, with a CO2 gas pocket at the top that is in contact/agitation with the vortex. A long clear return tube takes the CO2-enriched water from the bottom of the vessel back to the aquarium while leaving the CO2 pocket at the top of the vessel.
It is heavily dependent on flow, super loud, and seriously reduced my filter's flow rate (180-degree water direction inside doesn't help!). It wasn't even close to enough for my 150x60x60cm aquarium, and was just barely not enough for my 100x45x45cm aquarium with high surface agitation. Basically, it sucks.
I got it from Aqua Rocks Colorado years ago for about $40, but they are currently on sale for $35:
GLA sells the exact same reactor for $60:
Instead of throwing it out, I thought "Why not turn this into a horizontal reactor?!" The top has a 1/4" CO2 line push-fit connector, and comes with swappable 12/16mm or 16/22mm filter hose connection barbs.
All I needed "extra" was a 5/8" (16/22mm filter tubing size) bulkhead with washers of some kind. I'm sure you could find this part for much cheaper.
Enoch's Land 5/8" Hose Barb Thru-Bulk Bulkhead Fitting,304 Stainless Steel Straight Hex Union Fitting for Air Water Fuel 2 Pcs
:
And some silicone gaskets on both sides of the vessel/bulkhead washers. I already had these, but a kit is always a good idea to have on hand. I used silicone washers from this kit.
Step 1: Use the barb fitting's washer to mark the off-center bulkhead drill point on the bottom of the reactor:
Step 2: For a 5/8" hose barb/bulkhead, use a 3/4" hole saw drill bit (or any 3/4" bit, really) and drill your off-center hole:
Step 3: insert your barb fitting. It should go (from right to left in this photo):
Barb Fitting > Metal Washer > Silicone Gasket > Container Wall > Silicone Gasket > Hex Nut
And you're done!
All you need to do is block/plug one of the two "inlets" (pictured on the right above). One will be used for water in, and the stainless barb fitting will be used for water out.
You will also need a hose clamp to keep the hose from slipping off the stainless barb fitting, like these.
However, it is also MUCH cheaper than buying the premade horizontal reactors at ARC for $80-$120:
This reactor is 10cm+ in diameter and about 37cm+ in length. At max power (50% filled with CO2), it has a gas-pocket surface area of 380cm2. At a 15:1 ratio of tank:reactor surface area, this reactor can fully inject CO2 into a tank up to 5,700cm2 surface area (length x depth). For example, a standard 40-gallon breeder is 90cm long by 45cm deep, so it has a surface area of 90x45=4,050cm2. This reactor could easily inject way more than enough CO2 for a 40 gallon breeder. It would likely be somewhat underpowered for a 120cmLx60cmD sized tank, but would still work to reach 20-25ppm CO2 injection I'm sure.
This reactor has almost the exact same measurements as the Small Acrylic/Small Stainless Horizontal Reactors at ARC (shown above), and they claim this size can inject CO2 for tanks between [standard rectangular sized] 45cm to 90cm long tanks).
The benefits of this reactor are super obvious:
This old reactor works by making a "vortex/spiral" of water flowing in due to a 90-degree elbow piece, with a CO2 gas pocket at the top that is in contact/agitation with the vortex. A long clear return tube takes the CO2-enriched water from the bottom of the vessel back to the aquarium while leaving the CO2 pocket at the top of the vessel.
It is heavily dependent on flow, super loud, and seriously reduced my filter's flow rate (180-degree water direction inside doesn't help!). It wasn't even close to enough for my 150x60x60cm aquarium, and was just barely not enough for my 100x45x45cm aquarium with high surface agitation. Basically, it sucks.
I got it from Aqua Rocks Colorado years ago for about $40, but they are currently on sale for $35:
GLA sells the exact same reactor for $60:
Instead of throwing it out, I thought "Why not turn this into a horizontal reactor?!" The top has a 1/4" CO2 line push-fit connector, and comes with swappable 12/16mm or 16/22mm filter hose connection barbs.
Converting to a horizontal reactor
All I needed "extra" was a 5/8" (16/22mm filter tubing size) bulkhead with washers of some kind. I'm sure you could find this part for much cheaper.
Enoch's Land 5/8" Hose Barb Thru-Bulk Bulkhead Fitting,304 Stainless Steel Straight Hex Union Fitting for Air Water Fuel 2 Pcs
:
And some silicone gaskets on both sides of the vessel/bulkhead washers. I already had these, but a kit is always a good idea to have on hand. I used silicone washers from this kit.
Step 1: Use the barb fitting's washer to mark the off-center bulkhead drill point on the bottom of the reactor:
Step 2: For a 5/8" hose barb/bulkhead, use a 3/4" hole saw drill bit (or any 3/4" bit, really) and drill your off-center hole:
Step 3: insert your barb fitting. It should go (from right to left in this photo):
Barb Fitting > Metal Washer > Silicone Gasket > Container Wall > Silicone Gasket > Hex Nut
And you're done!
All you need to do is block/plug one of the two "inlets" (pictured on the right above). One will be used for water in, and the stainless barb fitting will be used for water out.
You will also need a hose clamp to keep the hose from slipping off the stainless barb fitting, like these.
Why do this?
For me, it was simply because I needed a horizontal reactor for my tank, and I had this lying around!However, it is also MUCH cheaper than buying the premade horizontal reactors at ARC for $80-$120:
How powerful is it? What is roughly the largest tank size it can power? What benefits does it have?
If you want to know how to calculate the size of horizontal reactor needed, or the general benefits of a horizontal reactor, see my post here!This reactor is 10cm+ in diameter and about 37cm+ in length. At max power (50% filled with CO2), it has a gas-pocket surface area of 380cm2. At a 15:1 ratio of tank:reactor surface area, this reactor can fully inject CO2 into a tank up to 5,700cm2 surface area (length x depth). For example, a standard 40-gallon breeder is 90cm long by 45cm deep, so it has a surface area of 90x45=4,050cm2. This reactor could easily inject way more than enough CO2 for a 40 gallon breeder. It would likely be somewhat underpowered for a 120cmLx60cmD sized tank, but would still work to reach 20-25ppm CO2 injection I'm sure.
This reactor has almost the exact same measurements as the Small Acrylic/Small Stainless Horizontal Reactors at ARC (shown above), and they claim this size can inject CO2 for tanks between [standard rectangular sized] 45cm to 90cm long tanks).
The benefits of this reactor are super obvious:
- It comes with all the standard-sized filter hose fittings for most canister filters these days
- It comes with an airtight means for injecting CO2 (the 1/4" push-connect tubing port is next to the hose fittings)
- It can be easily rotated to adjust the power of the reactor (and therefore setting the maximum injection/overflow amount).
- It is quieter, more efficient, and barely reduces flow when compared to this reactor used vertically.
- It's $35 for the reactor itself, and another $20 for parts if you don't have them. That's $55 total for a horizontal reactor that can power most tanks up to 60 gallons, instead of a $80 acrylic reactor or $120 stainless steel reactor. Cheaper if you already have the vertical reactor, or the parts required!
