The subtitle of the the SWG forum is "Pool Chemical Automation, chemical dosing systems, liquid chlorine dosing, CO2 systems, SWCGs and water chemistry for an SWG pool" which includes Stenner pumps and the like. We don't have a separate space just for Stenner pumps.
Incidentally, I have been curious as to why on new builds I always see this forum recommend SWCGs and very rarely Stenner pumps. SWCGs seem to increase the pH and require more frequent acid additions and do not work when the water gets colder, but not cold enough to close. I would think that the Stenner pump has fewer downsides. The only thing you need to do is fill the tank with liquid chlorine. I am not sure about everyone else, but my 15 gallon tank has lasted a full month between fills.
At the same time, I can see that the Stenner is more of a rigged up system and not designed specifically for pools and so might not look as "professional" as a SWCG. I'm just curious as to other people's thoughts on this.
pH rise is not a given. There are plenty of SWG owners that have never had to add any acid to their pools...for several seasons! It all depends on the input water to your pool, the pool surface and what forms of aeration are present. SWG's are, chemically speaking, pH neutral. Any pH rise they contribute to is simply from aeration inside the cell and that can be minimized by using a cell that's rated at least 2X your pool volume and keeping the FC loss rate low with higher CYA levels. I only run my SWG for what amounts to 2.4 hours/day and so the cell itself does not contribute to aeration as much as my waterfall, spa spillway and generally high-hardness fill water does.
When properly cared for, an SWG can that last 5-7 years without any trouble. That means the only chemical I need to lug from the trunk of my car to the backyard pool equipment pad is a container of acid. My pH stability has me adding acid about every 7-10 days and so, for the most part, I never have to bother adding anything to my pool. The economics of SWGs makes it such that they are equivalent in cost to any method of liquid chlorine dosing but only slightly more expensive than calcium hypochlorite dosing (cal-hypo is typically the most cost effective chlorination method
IF calcium hardness is not an issue and it's a lot easier to transport).
Stenners are a fine option too, but many PBs don't install them; they're more of a DIY piece of equipment. Since SWGs are typically paired with automation systems, the upfront costs are often part of an overall pool build and so their incremental cost is in the noise when you're building a $50k pool. Switching from solid chlorine to liquid chlorine via a Stenner pump is far cheaper than switching to an SWG but many people come to appreciate not having to lug gallons of bleach every 2-3 weeks. Another potential downside to Stenner pumps, especially in my area, is that bleach is far less stable at high temperatures than when sitting in your laundry room. Setting up a 15 gallon tank of bleach when my summer air temps can easily hit 115F means wasting a lot of potential chlorine. My SWG doesn't care much how hot it is.
As for cold weather, yes SWGs do shutoff below 55F. BUT, last winter (which is 4 months for me) I used
exactly one (1) gallon of bleach in my pool and I adjusted pH once. So, in open winter pools, chemical concerns are minor.
