Quote Originally Posted by Symon View Post
I was doing research on a UV system that looks like it will make pool care less time consuming.

I am dealing with my first algae bloom.

so I can read further into the forums, particularly about UV vs salt water
membership upgraded.

Regarding your pool issues, I want to respond to some of your questions, since UV posts seem to have taken an upturn recently. Some of this has already been covered, but I wanted to collect it in a single post.

1. I am one of VERY few who have actual field experience with an effective UV irradiation system for pools.

2. UV systems do NOT sanitize pools; at best, they may sanitize the water in the irradiation chamber.

3. UV systems have little or no effect on algae.

4. In all but the most extreme cases ($$$$), *outdoor* pools ALREADY get more UV from sunlight than they will from an added UV system.

5. The ONLY legitimate applications for pool UV systems I know of are (a) to reduce complex chloramines in heavily used indoor pools, OR (b) as part of an exotic treatment system on luxury indoor pools, to eliminate detectible chemical use.

6. The system I worked with was the later case, and used UV + hydrogen peroxide + polyquat to make chemical use undetectable to swimmers. I swam laps in that pool, and can tell you it performed exceptionally well with respect to that goal. BUT, it was very expensive and rather high maintenance. To give you an idea of what sort of location it was, I discovered that the Greek amphora-style vases that were on the deck had cost over $120,000! Fortunately, I did not break one, when I nearly knocked it over with my tool box!

7. There is no legitimate UV vs salt comparison as a standalone pool treatment system. Salt water chlorine generators (SWCG) provide an effective means of sanitizing pools continuously with chlorine. UV systems don't provide an effective means of sanitizing anything, except the gallon or so contained in the contact chamber. Chlorine is an effective oxidizer of pool wastes; UV is not. UV + chlorine *is* an even more effective system, than chlorine alone, but sunlight provides more than enough UV for this effect to take place on outdoor pools.

8. UV systems, even where effective, are still rather experimental, and are only likely to work well when installed and serviced by someone who is far more expert in water treatment than 99% of the pool guys out there. Such a person is unlikely to be a UV promoter.

9. Even where effective, UV systems will NOT reduce pool maintenance, especially compared to a pool operated with the BBB method taught here. UV systems should only be used where the benefits (say on a commercial indoor therapy pool) outweigh the costs and additional maintenance.

10. To get rid of algae, add PLAIN household bleach till you read and hold a DARK yellow OTO level (cheap OTO/phenol red drops kit purchased locally), and keep those levels for a week after all traces of algae are gone.

11. Read the Best Guess page, linked in my signature, for an explanation of what's going on.

12. After you've read that page, order a K2006 test kit (Amazon link in my signature -- but in Canada, this site -- http://piscines-apollo.com/ -- may be your only source) so you can manage your pool's chemistry easily and effectively.


Quote Originally Posted by Symon View Post
I got interested in the UV process because we use one at our cottage to prep lake-drawn drinking water after a sand/rust and then an activated charcoal filter. The water becomes potable after the process (had it tested), so I was interested in thoughts on its use in a pool.
Treating a once through system with no added 'dirt' load cannot be compared with treating a recirculated system, with constantly added 'dirt' (swimmers, etc.). The fact that you are treating for rust suggests that the lake may be acidic, which in turn suggests it may be clear, nearly sterile water ALREADY.


Good luck!