SWCG and Indoor Pool

[codyt]

I bought a house this past fall with an indoor pool that hasn't been used in a few years. It's 32' long and 16' wide and about 4' deep in the shallow end and 8' deep in the deep end and about 23000 gallons. It was built in 1980 I believe. We're having someone come look at it for repairs (there are some cracks and the skimmer has a hole in the side of it).

We'd like to install a salt chlorine generator as the pool currently doesn't have any sensitization system installed. I've read that indoor pools don't need very large salt chlorine generators since they don't get any sunlight. So what size system would I need? Are there any other concerns or special considerations for indoor pools?

[PoolDoc]

membership updated.

It's cheaper to buy a large system, and turn it down, than to buy a small system. SWCG life is directly related to 'on-time'; big systems have less on-time, and last longer, but commonly bigger system prices do NOT go up proportionately with their capacity.

[codyt]

membership updated.

It's cheaper to buy a large system, and turn it down, than to buy a small system. SWCG life is directly related to 'on-time'; big systems have less on-time, and last longer, but commonly bigger system prices do NOT go up proportionately with their capacity.

According to: http://www.poolsolutions.com/gd/swimming-pool-salt-water-chlorine-generators-faq.html An outdoor pool typically loses over 80% of its chlorine to sunlight. This means an indoor pool with the same use levels, will need less than 20% of the chlorine an outdoor pool does. In most cases, if you have an indoor pool, you'll want the smallest generator available. Otherwise, you simply won't be able to turn it down enough.

So this doesn't seem to agree with your statment of buying a large system. Are there salt systems designed to be turned down low enough to produce the correct amount of chlorine for an indoor pool?

[PoolDoc]

I need to update that page.

That was written, when many of the SWCG's had limited 'turn-down' capability. I need to edit that page to reflect that most of todays systems have digital controls that allow you to operate at, say 5% of full capacity.

You WILL need a unit that has that capability.

[codyt]

I need to update that page.

That was written, when many of the SWCG's had limited 'turn-down' capability. I need to edit that page to reflect that most of todays systems have digital controls that allow you to operate at, say 5% of full capacity.

You WILL need a unit that has that capability.

So if I had an outdoor pool I'd want to super-size the SWCG and get a 40,000 gallon capacity (my pool is 23,000 gallons). But since I have an indoor pool, is getting a 40,000 gallon capacity system super-duper-sizing? Would I be ok getting a 25,000 gallon capacity system and saving $100 since I wouldn't have to run it very high anyway since I'm indoors? Is using a 25,000 gallon capacity system on an indoor 23,000 gallon pool similar to using a 40,000 gallon capacity system on an outdoor 23,000 gallon pool?

[PoolDoc]

40,000 gallon units typically are BARELY big enough for 40,000 gallons . . . and 5% of 40,000 gallons is 2,000 gallons.

But . . . suit yourself.

I have no idea what your load, indoors, will be.

Outdoor load tends to depend on sunlight, unless bather load is at commercial levels. Indoor pool load is based on bather load. If your pool is unused, almost any SWCG will be too big, so you'll need a time clock on the power input. If the pool is used regularly for laps by a real swimmer, bather load (sweat + skin), bather load may be MORE than a typical outdoor pool, used only for intermittent recreation. If the pool is used by a former competitive swimmer, who pees in the pool (it's not just Micheal Phelps and Ryan Lochte -- virtually all serious USS swimmers do!), then the effective bather load is even higher. Ditto for a pool used by babies, or the Depends crowd.

[Poolsean]

cody, do you have an automatic cover on the pool? If so, then you will need a system that you can fine tune so as not to overchlorinate. If not, then as Ben mentioned, you'll need to consider the pump run time and actual pool usage. I normally recommend to get the largest size cell you can afford. In this case, again as Ben mentioned, make sure the system you select gives you enough control over the output. For instance, if the output is controlled by LED lights, a system with 5 lights on the output levels will give you 20% increments. 8 LED lights = 12.5% increments, etc... Digital displayed units should give you 0 - 100% control in 1% increments.

[PoolDoc]

Digital displayed units should give you 0 - 100% control in 1% increments.

. . . and if you put a time clock -- it can be a cheap Lowes one -- on the power input, you can turn things down even more.

[codyt]

cody, do you have an automatic cover on the pool? If so, then you will need a system that you can fine tune so as not to overchlorinate. If not, then as Ben mentioned, you'll need to consider the pump run time and actual pool usage. I normally recommend to get the largest size cell you can afford. In this case, again as Ben mentioned, make sure the system you select gives you enough control over the output. For instance, if the output is controlled by LED lights, a system with 5 lights on the output levels will give you 20% increments. 8 LED lights = 12.5% increments, etc... Digital displayed units should give you 0 - 100% control in 1% increments.

It's an indoor pool, so I don't have a cover on it, just the ceiling/roof. So what systems would you recommend that have a digital display, but aren't too expensive? (I see now that your signature says you work for AutoPilot, so maybe you won't be allowed to give any recommendations?)

PoolDoc, do you have any recommended systems?