Installing in-line chlorinator below water level

[WorBry]

I'm looking at installing a Hayward CL-100 in-line chlorinator in my AGP plumbing system, and am trying to decide whether to install it at the same level as the filter return port (as was recommended to me by the pool store) or to drop it down to near ground level.

I posted a couple of photos of the set-up in another thread (that was going off topic):

abs-fittings-t42537.html (pics are in the 7th post down)

I'm trying to understand the implications of installing below the water level. Although the CL-100 has an integral check-valve in the feedline (to prevent back-flow in to the chamber) the recommendation is to install ball stop valves on either side of the chlorinator so that it can be isolated when recharging. I'm fine with that, although I would have thought that closing the filter multi-port valve would serve the same function as a stop-valve on the inlet side of the chlorinator.

My question is, during operation, does the chlorinator chamber completely fill with water or is it normal and possibly necessary for an air pocket to persist in the chamber head-space? For 'bottom feed' chlorinators, at least, I would have thought that a head-space helps to ensure that the lower pucks in the stack are eroded first, provided of course that the air pressure is not so great as to prevent water from entering the chamber through the inlet control valve.

The reason I ask, is that when the lid is opened for re-charging (after switching off the pump, closing control valve and stop valves) will the chamber be filled to the brim or will the water be held in check at a low level so that fresh pucks can be added safely without risk of overflowing.

In the Rainbow 320 in-line chlorinator user guide it specifies "If installed below water level, a drain valve must be installed (literally hole drilled and tapped) to prevent spillage and dangerous splash back of high chlorinated water during recharging". It is not clear whether that applies to both "top feed" and "bottom feed" modes, but I can see no equivalent drainage requirement in the Hayward CL-100/200 instructions. All it says is:

1. Shut off all pumps and pump timers.
2. Turn chlorine feeder flow control valve to “OFF"
3. Verify chlorine feeder return line to pool is unrestricted.
4. Wait one minute to relieve system pressure before attempting to remove cover.
5. If installed in a flooded system (i.e. below water line) shut off valves to isolate chlorinator.
6. Remove cover.

Edit: Just spoke to Hayward technical support here in Canada, and they told me it is normal for the chamber to fill up when running and that if installed below water level, yes, it can be expected that the chamber will be full of water. I wondered whether running the pump with the inlet control valve closed, prior switching off and closing the stop valves, might help to drain some water from the chamber, and they said maybe a little, but not enough to evacuate it.

I guess, after loosening the lid, one could evacuate through the bottom drain, but I suspect the plug and seal would not last too long if that were done on every recharge. Maybe, like the Rainbow, install a drain valve in that hole????

 

[PoolGuyNJ]

I hate CL100s. They have a 3/4" venturi restriction in them. What's even sadder is I a PB that uses these on 2" pipes and 2 HP pumps.

I prefer Rainbow 320s. Two way valves in front and behind. The top or bottom feed configuration doesn't matter.

What does matter is that you have a way to get the water out of the pipe if you winterize.

Scott

 

[WorBry]

Unfortunately, none of the pool stores in my local stock Pentair - it's all Hayward, Olympic and a few other copycat brands. I was originally going for the Olympic in-line chlorinator; twice the capacity (9 1b) for about the same price as the CL-100, but no integrated check-valve, and I just couldn't see it perched on the filter return port - more importantly, neither could my wife - hence one of the reasons why I am also considering installing the CL-100 below the water level to make it less conspicuous. Classic case of functionality versus aesthetics.

 

[WorBry]

I hate CL100s. They have a 3/4" venturi restriction in them. What's even sadder is I a PB that uses these on 2" pipes and 2 HP pumps.

I prefer Rainbow 320s. Two way valves in front and behind. The top or bottom feed configuration doesn't matter.

@PoolGuyNJ

Your comment prompted me to look into the issue of flow restriction and for sure this is one of the biggest criticisms of in-line chlorinators, the CL-100 being a notable example. Came across this interesting article recommending installation with a bypass to avoid this problem:

http://www.savemorepoolstore.com/pages/ ... takes.html

I guess it's not to late to take the CL-100 back - I haven't installed it, or glued anything yet, but it would be quite simple to rig up a bypass loop, with a couple of tees and elbows. Question is, if I instead put the CL-100 in a loop "teed-off" the return line, would there still be sufficient flow through the chlorinator for it to work? The loop would be just large enough to ensure 6" of straight pipe either side of chlorinator and stop-valves at the two branch-off points. That way the "chlorinator-loop" could be isolated for servicing or whatever, without interrupting circulation.

Do you think this would work????

 

[PoolGuyNJ]

Nope. Take the CL-100 and mail order a Rainbow 320. Save yourself a BUNCH of grief.

Scott

 

[WorBry]

Thanks. Yeah, I thought as much. Quite honestly, I'm about ready to throw the towel in on the whole chlorinator thing. I think they are probably well suited for in-grounds and AGP where the filter/pump pad is under a deck, but, in my case, the gear is 'out-in-the-open' without easy means of supporting hard-piping, short of putting up a fence-cum-screen around the pad. And now this flow restriction issue with the CL-100. Yes, maybe consider ordering a Rainbow 320 at some point, but for now I'm thinking to take the CL-100 back, exchange for a couple of floaters and a good test kit. Main reason I got the chlorinator was for vacations. Right now I'm inclined to shock, shut the pool down, cover it and deal with the goo on return.

My only remaining thought is whether, just possibly, an off-line chlorinator might work. Again, short of mail ordering, the only option is a Hayward CL-220. Do they really clog as easily as claimed? Is it imperative that the inlet line is cut-in between the pump and and filter? Would there still not be sufficient pressure if installed immediately after the filter with the outlet line close to the pool return? I don't have a heater to consider.

Of course I've looked at SWG. If I was installing a new resin AGP, probably yes, but this is a 7 year old steel sided pool (inherited from a relative, 're-installed' last season) and is it really worth the cost including the added cost/hassle of 'bonding' and replacing everything that could corrode with stainless steel.

The Liquidator sounds great, but no-one supplies it around here (Quebec). One pool store mentioned something about restrictions on storing volumes of concentrated liquid chlorine and again, it is probably not something I"d want to have sitting 'out-in-the-open'.

My wife cant understand why I don't keep it simple and continue to load the skimmer basket with pucks 'like everyone does'. Probably one reason why the skimmer was in such bad shape that it needed to be replaced when the pool was installed.

So, maybe BBB plus floaters, at least until I've used up the mountain of pucks.