Convert to SWG?

[MartyW]

Hi Everyone,
I'm considering changing from chlorine to salt. Good idea or bad? I have 18,000 gal inground vinyl, hayward super pump, hayward perflex de filter, Raypak heater. I've had metal staining issues in the past. Do I need to worry about corosion of the metal parts? If I do switch, who makes the best? I assume I still need to test for Ph, Alk Etc. Any advise is appreciated,
.
Thanks, Marty

[CarlD]

Marty, you are NOT switching from chlorine to salt. I hate to say this, but if you think that you haven't researched SWG sufficiently. SWGs are chlorine systems: Salt is NaCl--Sodium Chloride and works by breaking salt back into sodium and chlorine, and that chlorine is used to sanitize your water. It's TOTALLY compatible with other forms of chlorine.

I won't go into who makes the best SWG but I can tell you that with an 18,000 gallon pool you don't want one rated for 15,000-20,000 gallons--you want one rated for a larger pool. The unit will work better and last longer because it won't be as stressed. The main reason for SWG is to reduce your need to monitor and add chlorine--it's really great if you have to leave your pool for a few days or a week without maintenance. On the other hand, if you want it to save you chlorine costs, it will take a few years before the cost of the SWG is covered by the chlorine you saved. I like to use liquid chlorine, 12.5% strength, sold in 5 gallon carboys for about $17 each. Since an SWG can run $1000 to $2000 just for the equipment, it takes a lot of carboys saved to pay for it.

[MartyW]

Thanks Carl,
I do realize I'm still using chlorine. I'm trying to figure out what the advantages and disadvantages are (other than initial cost). I also use liquid chlorine and a Hayward feeder and trichlor pucks. How does a salt system affect things like pH, Alk Cya, etc? I fight metal stains every year. I think they came from my heater.

Thanks, Marty

[CarlD]

Marty: What we see here is that people do frequently see a rising pH with SWG systems and end up adding acid or using trichlor pucks. However, the rule of thumb for safe sanitation is the SWG should maintain FC at 5% of the CYA (stabilizer) level. Also, most manufacturers recommend higher CYA levels, from 60 to 80 ppm, usually closer to 80. You'll therefore have to keep FC between 3 and 4ppm consistently. If you have low CYA and your pH keeps going up, Tri-chlor pucks may be the solution. They add CYA and lower pH.

IF your system raises pH and you have to keep lowering it, you MAY see a falling T/A. But frequently rising pH is due to aeration--lots of splashing, water falls, etc. Still many SWG users do comment on rising pH.

[CarlD]

I'm actually considering taking the plunge myself. Looking at travel plans and may need an SWCG to maintain it during those times.

[MartyW]

Carl, Thanks for the feedback. It gives me a lot to think about. If you do take the plunge, which one would you use? Marty