@Want2BS8ed, many thanks for the picture. Did you notice a slight reduction in pH when you connected the air to the skimmer? I am just wondering if air only being pulled from outside and then through the scrubber has a lower C02 level than air being pulled through the scrubber and from the skimmer? I am just running another test to see how long my media lasts directly through the scrubber but will then give your solution a go.
No, no noticeable difference and I ran the bypass intake dry for quite some time before the replumb.
The current location is really nothing more than a matter of convenience. As long as I was drilling and tapping the skimmer cover, it was easy to do two and the installation wound up a bit tidier. Previously the valve was just flopping around.
The valve was purchased from McMaster-Carr (there is likely a similar outfit in the U.K.) and comes with push connect fittings - 3/8" in my case, but 1/4" and 1/2" are available. Plumbing couldn't be easier.
Neptune also has a 1/4" valve, but it is fairly restrictive and I wouldn't recommend it for this use.
If you have one of the newer 2016 Apex Energy Bar 832's or a Neptune Fluid Monitoring Module (FMM), etc. you can also purchase the valve in a 24-volt version and free up one of the main outlets on your Energy Bar.
I just purchased one of Neptune's 24-volt extension cords and nipped one end off and wired it to the valve. Again, couldn't be much easier.
And just for reference, the bypass is set to come on at 8.3 and go off at 8.2. If I were a little less greedy and lowered it to 8.2/8.1 the media would likely last even longer.
M