This weekend we'll be installing a new filter and adding an Autopilot SWCG. Following is our current set up. We bought the house last year so I don't know the reasoning behind any of the set up but it seems fairly straightforward. We have two skimmers (no main drain) that come in on one line to the pump. We replaced the pump last year. We'll probably replace most if not all of the plumbing (other than that coming from the pool into the pump).
1. We'd like to fit the SWCG where the chlorinator is now. We have 1.5" plumbing so will be using reducers coming out of the Autopilot. I figure we'll have about 18" of play between the two elbows. Would this be enough room to install the SWCG and reducers with unions? Thought unions would leave us options if we have a problem with the manifold since there won't be a whole lot of play in that space. Should we even bother with unions? I assume they would be ok with the pressure and such.
2. Is there a better way to do our plumbing? We've got a very basic set up - so wasn't sure there was really much to worry about.
3. Should we plumb the filter so it can be removed in the winter?
4. I notice the controller unit on the Autopilot has a gap in the back - which I assume is to allow air flow around the unit. I've seen several people talk about cleaning bugs and wasp nests out their SWCG. We've got plenty of wasps around and was wondering if there's any way to deter bugs/wasps from trying to nest in the unit. I know it needs circulation of air so wasn't sure there was much to be done in this area.
5. Anyone have any idea what the o-ring hanging on the return (step) valve is for? I'm guessing the pool store guy left that hanging there last year but I have no idea what it goes to.
Any other tips or suggestions are welcome - I'm probably forgetting something I meant to ask.