The other day I posted asking for suggestions on how to connect a CO2 scrubber to a Reef Octopus external recirculating skimmer. Here is what I finally came up with:
1.25" Inner diameter tubing fits over the (removable) cap at the top of the silencer perfectly. I used a 1.25" x 1.25" x 0.75" T to get down to 3/4" tubing to run to the scrubber, to avoid a bunch of reducing adapters inline elsewhere. Top of the T is simply capped off with a barbed plug.
The 3/4" tubing hanging down from the scrubber has a pair of 3/8" push-to-fit solenoid valves, one above the incoming horizontal length of tubing and one below it, to control whether air being supplied to the skimmer is drawn through the scrubber at all. I found 3/4" x 3/8" single-barb kynar barb connectors online and used a sanding drum on Dremel tool to sand off the barb and other projections on the shank of the connectors. The smoothed shanks fit into the solenoid valve connectors perfectly, and this let me connect the 3/4" tubing directly to the solenoid valves.
Solenoid valves are 24V DC and are controlled by Apex. When pH drops below 8.15, the upper solenoid opens and the lower one closes. This forces all air coming into the skimmer via the silencer to pass through the scrubber. When pH rises above 8.15, the reverse happens, i.e., upper solenoid closes and lower one opens so that air coming into the skimmer via silencer comes in through the open lower end of that "appendage."
Note that I refer to air coming into the skimmer via the silencer. This model of skimmer has an overflow line running from the skimmer collection cup down to the silencer, so that excess skimmate will go back into the skimmer recirculation box via that line/silencer, and some air is aspirated into the system via that line. Initially, I used a chip bag clip to close off that line -- there is a float switch in the collection cup that will shut off the Reef Octopus recirculation pump in the event of an overflow, so the overflow line is not needed for protection -- to prevent any air from bypassing the scrubber when pH drops below 8.15, but the bubble production fell off tremendously, to the point of getting little benefit from the skimmer. Therefore, I removed the clip and figured I'll accept some air coming in without going through the scrubber, and still the system held pH far higher/stable last night than without it. See screen shot (and ignore pH spikes, which may be due to stray voltage that I'm currently trying to identify):
1.25" Inner diameter tubing fits over the (removable) cap at the top of the silencer perfectly. I used a 1.25" x 1.25" x 0.75" T to get down to 3/4" tubing to run to the scrubber, to avoid a bunch of reducing adapters inline elsewhere. Top of the T is simply capped off with a barbed plug.
The 3/4" tubing hanging down from the scrubber has a pair of 3/8" push-to-fit solenoid valves, one above the incoming horizontal length of tubing and one below it, to control whether air being supplied to the skimmer is drawn through the scrubber at all. I found 3/4" x 3/8" single-barb kynar barb connectors online and used a sanding drum on Dremel tool to sand off the barb and other projections on the shank of the connectors. The smoothed shanks fit into the solenoid valve connectors perfectly, and this let me connect the 3/4" tubing directly to the solenoid valves.
Solenoid valves are 24V DC and are controlled by Apex. When pH drops below 8.15, the upper solenoid opens and the lower one closes. This forces all air coming into the skimmer via the silencer to pass through the scrubber. When pH rises above 8.15, the reverse happens, i.e., upper solenoid closes and lower one opens so that air coming into the skimmer via silencer comes in through the open lower end of that "appendage."
Note that I refer to air coming into the skimmer via the silencer. This model of skimmer has an overflow line running from the skimmer collection cup down to the silencer, so that excess skimmate will go back into the skimmer recirculation box via that line/silencer, and some air is aspirated into the system via that line. Initially, I used a chip bag clip to close off that line -- there is a float switch in the collection cup that will shut off the Reef Octopus recirculation pump in the event of an overflow, so the overflow line is not needed for protection -- to prevent any air from bypassing the scrubber when pH drops below 8.15, but the bubble production fell off tremendously, to the point of getting little benefit from the skimmer. Therefore, I removed the clip and figured I'll accept some air coming in without going through the scrubber, and still the system held pH far higher/stable last night than without it. See screen shot (and ignore pH spikes, which may be due to stray voltage that I'm currently trying to identify):
