Why Is My Pool Contractor So Fixated On UV+ Chlorine System?

[Singuy]

I am about to build a 700 squareft pool and this contractor just LOVES UV system. I told him I'm looking at salt but he is trying to his best to convince me how UV is better. This is a pool company of 30 years that built over 16,000 pools.

I read on the forum that a UV system is useless and salt is the way to go. Are there new technologies out that is proving to be better than salt?

The pool will be outdoor, central Florida, no screen cover.

 

[Isaac-1]

Yet again we see the fact that pool builders may be great at building pools, but probably know little about maintaining them. Try asking him if he has his own pool.

 

[tim5055]

I am about to build a 700 squareft pool and this contractor just LOVES UV system. I told him I'm looking at salt but he is trying to his best to convince me how UV is better. This is a pool company of 30 years that built over 16,000 pools.

I read on the forum that a UV system is useless and salt is the way to go. Are there new technologies out that is proving to be better than salt?

The pool will be outdoor, central Florida, no screen cover.

Is he telling you you will only need UV? Even with a UV system you have to have a sanitizer and that is chlorine. So, if you need chlorine anyway why bother with the UV? Contrary to the belief of many pool builders UV has little effect on an outdoor pool where you get lots of UV light for free from the sun. Heck, yo are in Florida - you get extra.

So, now where do you get the chlorine from? It can be one of many sources. There is a lot of confusion over "salt pools". A salt pool is a chlorine pool, you just don't add it manually. The "salt water chlorine generator" makes chlorine through a chemical reaction between the salt in the water and the electrified metals in the generator. Yup, a salt pool is a chlorine pool. The same chlorine in a gallon of bleach.

Chlorine is chlorine is chlorine. A Salt Water Chlorine Generator, Bleach, dichlor (powder shock), trichlor (tabs), cal hypo all deliver the exact same chlorine chemical - its just that each of them come along with a byproduct. Some you can live with easily, like the minor amount of salt that liquid chlorine leaves behind. Some you need to monitor and regulate, like the CYA dichlor and trichlor leave behind.

 

[Singuy]

Is he telling you you will only need UV? Even with a UV system you have to have a sanitizer and that is chlorine. So, if you need chlorine anyway why bother with the UV? Contrary to the belief of many pool builders UV has little effect on an outdoor pool where you get lots of UV light for free from the sun. Heck, yo are in Florida - you get extra.

So, now where do you get the chlorine from? It can be one of many sources. There is a lot of confusion over "salt pools". A salt pool is a chlorine pool, you just don't add it manually. The "salt water chlorine generator" makes chlorine through a chemical reaction between the salt in the water and the electrified metals in the generator. Yup, a salt pool is a chlorine pool. The same chlorine in a gallon of bleach.

Chlorine is chlorine is chlorine. A Salt Water Chlorine Generator, Bleach, dichlor (powder shock), trichlor (tabs), cal hypo all deliver the exact same chlorine chemical - its just that each of them come along with a byproduct. Some you can live with easily, like the minor amount of salt that liquid chlorine leaves behind. Some you need to monitor and regulate, like the CYA dichlor and trichlor leave behind.

No he suggested a standard chlorinator(tablet system) with UV. I was thinking about going salt to decrease maintenance.

His claim is that the UV will help reduce algae therefore less maintenance and lower chlorine usage. He is also claiming that the UV system will even be more maintenance free than salt and initial cost is cheaper.

 

[JoyfulNoise]

No he suggested a standard chlorinator(tablet system) with UV. I was thinking about going salt to decrease maintenance.

His claim is that the UV will help reduce algae therefore less maintenance and lower chlorine usage. He is also claiming that the UV system will even be more maintenance free than salt and initial cost is cheaper.

Actually, UV is most effective against certain bacteria that are more resistant to chlorine (legionella is one of them). However, those bacteria are not all that common unless you plan on opening your pool up to the general public.

UV is most effective when dealing with indoor pools that don't see any sunlight. In those situation, you use UV as a secondary source of oxidation of bather waste.

UV systems require long contact times in order for them to be most efficient. So the proper way to install them would be as part of a by-pass loop in the plumbing that only allows a small fraction of the water flow goes through the UV system. This would allow for a long contact time. Problem is, in order for all your water to see UV, you now have to run your pump a lot longer therefore your costs increase due to pump run time.

Finally, algae and bacteria prefer to be planktonic - ie, they prefer to adhere to and grow on surfaces rather than be free floating. So UV systems do nothing for algae that is stuck to the walls of your pool.

Why the PBs love these system? I suspect they have a much larger profit margin associated with them. SWGs are becoming much more common these days and their retail prices are decreasing quite a bit. I suspect a PB makes more money selling you a UV system than they do a salt water chlorine generator.

Stick to your guns, UV is not worth it.


Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006

 

[tim5055]

His claim is that the UV will help reduce algae therefore less maintenance and lower chlorine usage. He is also claiming that the UV system will even be more maintenance free than salt and initial cost is cheaper.

He is either ignorant of the facts or is lying. I go with Matt's theory, higher profit margin on UV.

 

[Divin Dave]

Sounds like your PB ran into a really great UV system salesman.

The literature and sales pitch all sound great, but in reality, the products usually dont quite live up to the hype behind it.
The things that the other folks above are mentioning is the part that's left out of the sales pitch and literature. Its not what they say, but what they dont say that should make you think.

Kudos to you for coming here and asking more about it. Unlike the PB or the UV salesman, no one here has a dog in the fight, so we'll tell you "the rest of the story".

Good day!

 

[Donldson]

I think it isn't really profit, the margins are similar with both UV and SWG systems but SWG systems cost more so would net the builder more. I think it is the idiot-proofness of tablets and UV. There are a lot of things that can go wrong with SWG systems that people are going to come back and yell at the builder for. If there isn't enough stabilizer then it is going to seem like it doesn't work on sunny days. If the pH is too high or too low then the plates can be damaged. Just a lot of things can go bad quickly enough for the buyer to come back on the builder.

But with tablets and UV, then things will probably go just fine for a year or two. Put your tablets in, shock it weekly, water stays mostly clear. Once the CYA buildup causes problems then the PB is past the point where the owner can really blame him for anything, so he can take a not-my-problem approach. Seems like it is all just a bunch of rear-covering on the PB side. So why add the mostly useless UV system instead of just a tablet feeder? Well, now we can talk about profit...

 

[Marcion333]

why is UV being recommended? follow the money

 

[JoyfulNoise]

Here's a post I wrote on a thread where the OP was really keen on running his UV system. I tried to write-up a response that was a neutral as possible while still hitting on as much of the technical issues with UV as possible. Perhaps you might find the read interesting.

Can I leave pucks in my in-line chlorinator when it's off?

 

[YippeeSkippy]

Anyone who has an outdoor pool in Florida gets *plenty* of UV action *free of charge*.

You still need chlorine so decide how you want to administer it? Salt water chlorine generator? Liquid chlorine (aka "bleach") which you add routinely. Simple and effective.
Tabs and powders are not a good choice for the *routine* daily chlorine dosing because they add often unwanted chemicals also and can cause problems.