I would like to take a little time to explain a few things about why I chose to do what I did with this reactor. On the first T out of the top I put the PH probe. The reason for this is that the probe has to have a fairly accurate reading of internal water PH. Putting this behind water intake or after the CO2 would give false readings. The water in is the next T out of the top. The reason for this is that water pressure in is greater that internal pressure. Keep in mind that CO2 is being injected into the system adding to internal pressure. For that reason my selection of having this in the basement was not hampered. Return water pressure is more than enough to push it all the way back up through the small poly line. The next in line is the air bleed off valve directly over the pump with a lot of space beneath it to fill in case I feel the need to pour water directly into it. The CO2 is injected just before the pump. The reason for this is that the pump can help chop up the CO2 and mix it in the water sort of like your protein skimmer is doing right now. At the bottom of the reactor chamber is a drain valve in case I need to remove the water for some reason. The input comes straight up from the bottom to stir the media more. I noticed that coming in from the side has turbulence below the media and does little to keep the water flowing in the correct direction. The water out T is also at the bottom. If it were up high air bubbles or CO2 would be forced back to the tank and this location avoids most of that.
Don'ts
求on't use metal fittings, not brass and NO way copper. [Remember what copper is used for in your quarantine tank]
求on't use multi purpose cement for connections.
求on't use any cement on the inside of the reactor or inside of the connections where it would contact water inside the unit.
求on't use anything inside that is not made for the aquarium or made of plastic. Preferred plastics would be PVC and acrylic.
求on't use a pump that fails to restart after a power outage. Always use a solenoid on the CO2 regulator. CO2 liquefies just over 500 lbs of pressure. In a power outage the reactor can become a hand grenade!
Keep in mind the extremely corrosive nature of what is in the reactor. It is salt, CO2 to lower the PH to a corrosive level and Calcium. Calcium can be used to melt ice. A popular brand of PVC cements is Oatey. Most of us have used it at some point in our aquariums. Something I never thought of was the corrosive nature of what I was doing. This is from Oatey's website on their MSDS [material safety data sheets] on the most of their cements.
Decomposition can occur with carbon monoxide, carbon dioxide and hydrogen chloride.
Further it lists materials to avoid such as potassium,
Calcium ,sodium hypochlorite.
Do's
求o use a CO2 regulator with a solenoid that shuts off during a power outage.
求o use a surge protector on all of this sensitive equipment such as pump PH controller and solenoid.
求o use only plastic and NO metal.
求o use a pump that restarts by itself after a power outage.
求o make sure it is mounted to ensure it does not fall over and rupture while you are not home.
求o draw your water from a sump return line if you have one and be sure to put a shut off valve on this line.