SWG Operation - Lessons Learned

[clone1008]

Pat,

Very informative write-up, especially since I'm considering the conversion myself. In your "Lessons Learned", can you tell me have there been any negatives? What about corrosion over an extended period of time? Any long term damage to the tile grout or coping? I'm just a little leary after getting caught up in the "Baquicil Movement" about 7 years ago and the horrors involved with that.

[PatL34]

Pat,

Very informative write-up, especially since I'm considering the conversion myself. In your "Lessons Learned", can you tell me have there been any negatives? What about corrosion over an extended period of time? Any long term damage to the tile grout or coping? I'm just a little leery after getting caught up in the "Baquicil Movement" about 7 years ago and the horrors involved with that.

The only real negative I found was having to replace the powerboard on the control unit 3 times because of bad quality control on the original LS1000 unit.

Corrosion at the salt levels that the Pool Pilot I use (3000 - 3500) has not given any instances of corrosion, other than having to wash the aluminum pool rakes and attachments, which were never designed for a saltwater pool any way. If you do find corrosion to the tile grout or coping, that is evidence of bad workmanship on the part of the pool builder.

In addition, I had to add a fresh water shower to prevent my wife and her swimsuit from being corroded away. BTW she was a pediatric nurse and understands that salty water hurts the eyes less than fresh water.

I think you will find that SWCG operation is a far cry from Baquacil and you should find it less troublesome. Having said that make sure you keep your pool chemistry up to par, and you should have no problems.

Hope this helps in your decision.

Pat

[clone1008]

The only real negative I found was having to replace the powerboard on the control unit 3 times because of bad quality control on the original LS1000 unit.

Corrosion at the salt levels that the Poolpilot I use (3000 - 3500) has not given any instances of corrosion, other than having to wash the aluminum pool rakes and attachments, which were never designed for a saltwater pool any way. If you do find corrosion to the tile grout or coping, that is evidence of bad workmanship on the part of the pool builder.

In addition, I had to add a fresh water shower to prevent my wife and her swimsuit from being corroded away. BTW she was a pediatric nurse and understands that salty water hurts the eyes less than fresh water.

I think you will find that SWG operation is a far cry from Baquacil and you should find it less troblesome. Having said that make sure you keep your pool chemistry up to par, and you should have no problems.

Hope this helps in your decision.

Pat

Pat,

Thanks for the help. You raise another interesting topic...will the salt water at that low of a level really mess up swim suits? Also, do you really feel the need to fresh water rinse in this type of water? I know the salty feeling of swimming in the Gulf but I didn't think this would be an issue in a pool. In fact most of the websites talk about the "good" feeing skin and no more bleached out suits.

Ric

[PatL34]

Pat,

Thanks for the help. You raise another interesting topic...will the salt water at that low of a level really mess up swim suits? Also, do you really feel the need to fresh water rinse in this type of water? I know the salty feeling of swimming in the Gulf but I didn't think this would be an issue in a pool. In fact most of the websites talk about the "good" feeing skin and no more bleached out suits.

Ric

I think you were taking me too seriously. The fresh water shower is more a convenience to remove the salt from the body and suit, before going in and taking a regular shower. Even public pools without salt have showers for this purpose. And yes you do have "good' feeling skin in a salt water pool, probably better than in the sea.

But even when swimming in the Gulf, the salt content is 3 - 4 times higher than in a salt water pool, but you still take a fresh water shower to remove the sea salt. Sea water to my knowledge has never ruined a swimsuit.

Hope this clears things up.

Pat

[clone1008]

I think you were taking me too seriously. The fresh water shower is more a convenience to remove the salt from the body and suit, before going in and taking a regular shower. Even public pools without salt have showers for this purpose. And yes you do have "good' feeling skin in a salt water pool, probably better than in the sea.

But even when swimming in the Gulf, the salt content is 3 - 4 times higher than in a salt water pool, but you still take a fresh water shower to remove the sea salt. Sea water to my knowledge has never ruined a swimsuit.

Hope this clears things up.

Pat

Point well taken...and thanks for the hygene tips...LOL...just kidding...thanks for all the info you've been very helpful!

Ric

[steveinaz]

Thanks for this thread, great info for pool-newbies like myself.

[Spensar]

Very interesting. Are there considerations for winter storage in the North with several months of below freezing temperatures?

On Ebay I see there are several for $500 to $700. Any particular brand recommended? I saw Hayward Aquarite, The Pool Thing, Zodiac and Pentair for sale in that range.

Any caveats or raves or are they all about the same? Does one use the cell up quicker? Warranty and service support issues?

[cschnurr]

I understand that when I take H20, and NaCl and pass them across the electrically charged plates, I can see how H2 and Cl2 can be formed.

Since the H2 comes from water, the remaining oxygen will dissipate.
However the Cl2 come from NaCl. What happens to the sodium, where does it go?

[chem geek]

I understand that when I take H20, and NaCl and pass them across the electrically charged plates, I can see how H2 and Cl2 can be formed.

Since the H2 comes from water, the remaining oxygen will dissipate.
However the Cl2 come from NaCl. What happens to the sodium, where does it go?

At the cathode (the negatively charged plate), hydrogen is produced from either of the following reactions:

2H+ + 2e- --> H2(g)
2H2O + 2e- --> H2(g) + 2OH-

Note that oxygen gas is NOT produced and does not dissipate. Instead hydroxyl ion (OH-) is created. Either of the above can be considered to be occurring since there is an equibrium that always exists in water between its split components, though the vast majority remains as the water molecule at normal pool pH:

H2O --> H+ + OH-

At the anode (the positively charged plate), chloride ion gets converted to chlorine gas that then dissolves in water to from hypochlorous acid and hydrochloric acid as follows:

2Cl- --> Cl2(g) + 2e-
Cl2(g) + H2O --> HOCl + H+ + Cl-
----------------------------------------
2Cl- + H2O --> HOCl + H+ + Cl- + 2e-

As you can see, the sodium doesn't participate at all in these reactions. When you add salt to water, it dissolves into its two components:

NaCl(s) + H2O --> Na+ + Cl- + H2O

Nothing happens to the sodium ion in a salt cell. Only the chloride ion participates in any reaction. The sodium ion does contribute to the general conductivity of the water. The area around the cathode accumulates negatively charged ions while the area around the anode accumulates positively charged ions so the sodium ion and hydrogen ion (which are positively charged) will tend to migrate from the anode to the cathode while chloride ion and hydroxyl ion (which are negatively charged) will tend to migrate in the opposite direction.

Now it is possible for another reaction to occur at the anode and competes with the production of chlorine as follows:

2H2O --> O2(g) + 4H+ + 4e-

So it is possible for oxygen gas to be produced in addition to chlorine, but due to the differential liklihoods (activation energies) of these two reactions, the production of chlorine is the primary reaction.

There are some websites that talk about "splitting" the sodium chloride as part of the electrolysis in the salt cell, but basically they have no idea what they are talking about. It is simply not true. Sodium Chloride (salt) "splits" all by itself when dissolved in water (in fact, that is how it is able to dissolve in water) and sodium has nothing to do with the electrochemistry of making chlorine.

Richard

[waste]

Carl, though I don't have all the reactions in front of me - the sodium becomes NaOH (I believe that it's lye). One of the 'real' chemists could tell you better, but it does combine an subsequently effects the reactions. (If I recall correctly, there are a few (2) loose electrons that help other chems 'match up')

[edit]Whoops, Richard alredy answered[edit]