I'm looking at purchasing an in-line chlorinator for my AGP. I know many on this forum don't favor chlorine pucks in general (CYA levels etc), but I used them all last season (my first), in the skimmer basket, without any problems. Just got fed up having to remove and replace the pucks when the pump was run discontinuously. Plus, I wanted a solution for vacations. A neighbour said he'd used his chlorinator (Hayward) for ten years and recommended them.
The two brands I'm considering, due to local availability, are Hayward and Olympic (WaterPik/Jandy) - the Olympic is around $40 cheaper here. Looking at the product information, both recommend putting a check-valve (one-way) between the filter (or heater, which I don't have) and chlorinator, to prevent back-flow of chlorine. The neighbour's set-up doesn't include one, but it does seem a wise precaution, especially if the chlorinator is fitted directly to the filter valve return port.
Can anyone recommend a reliable (mechanically), corrosion-resistant check-valve? I can imagine if the valve corrodes, or worse, clogs, there would be problems. I would be using quick-connect unions to connect the chlorinator-check-valve combo to the filter return port and the chlorinator to the return line (flexible hose), so that the unit can be removed at winter closure, and should problems arise.
Another thing I was wondering. I'll be putting the pump on timer this year, at least early and late season. Is it OK to leave the chlorine feed (dial control) valve open (apart from when refreshing the pucks) or will this result in chlorine/gas build up when the water is not flowing. Having to close manually the valve every time the pump goes off would clearly defeat the object.