I hope I am posting in the right spot. DH and I are wondering how much salt does the water softener actually need? There is this huge tank but does it have to be all the way full? Also, he said it seems to be creating a "salt bridge" occasionaly so he takes a stick and breaks that apart. I just want to make sure it is working to its full potential. Thanks!

barco: Wow so now the guys over at troublefreepool idiots, ouch. Well here is a response by Chem Geek talking about this exact issue and why you and I would be wrong and how it is CO2 outgassing, where did he go wrong: "I just wanted to correct what you said technically because what you said was not exactly true and I don't want the main point of running with lower TA helping to reduce the pH rise get lost because of technical inaccuracies. The salt cell has the following two primary reactions: 2Cl- --> Cl2(g) + 2e- 2H+ + 2e- --> H2(g) --------------------- 2H+ + 2Cl- --> Cl2(g) + H2(g) The chlorine gas almost immediately dissolves in the water with the following reaction to have a net reaction as shown: Cl2(g) + H2O --> HOCl + H+ + Cl- -------------------------------- H+ + Cl- + H2O --> HOCl + H2(g) Because water dissociates, the above reaction is normally written with a net reaction as follows: H2O --> H+ + OH- ---------------------------------------------- 2H2O + Cl- --> HOCl + OH- + H2(g) So the bottom line net reaction with the generation of chlorine in a salt cell (ignoring side reactions) is that water and chloride ion (from salt) combine to form hypochlorous acid (HOCl) plus hydroxyl ion (which is basic or alkaline) and hydrogen gas. Since hypochlorous acid is a weak acid, this net reaction is weakly basic (alkaline). This is where most SWG manufacturers (at least their salespeople) believe that the rise in pH comes from, but they are wrong (keep reading to find out why). This is pretty much exactly the same thing that happens when you add chlorinating liquid or bleach to a pool as follows: NaOCl --> Na+ + OCl- OCl- + H+ --> HOCl H2O --> H+ + OH- -------------------- NaOCl --> Na+ + HOCl + OH- except that you get some sodium ion as well (plus some extra salt, NaCl, that is in sodium hypochlorite solutions due to how they are made) and you don't get the hydrogen gas. Now we need to look at what happens to chlorine (regardless of source) when it gets used up. Most chlorine in pools gets broken down by sunlight and even though Cyanuric Acid (CYA) combines with chlorine to form a chemical compound that slows down this process (and is not an effective disinfectant or oxidizer), it still happens as follows: 2HOCl --> O2(g) + 2H+ + 2Cl- The next most common thing that happens to chlorine is that it combines with ammonia or related compounds such as urea from sweat as follows where I show the reaction going all the way to "breakpoint" assuming that shocking occurs (which it usually does if you have sufficient chlorine in your pool and especially when exposed to sunlight which helps the breakpoint process). I'm not going to show what happens when chlorine combines with organics, but the process is somewhat similar (carbon dioxide is produced if the organic is fully oxidized, but more typically intermediate compounds are produced that don't breakdown quickly). 2NH3 + 3HOCl --> N2(g) + 3H+ + 3Cl- + 3H2O So, even though the generation of chlorine resulted in hydroxyl ions, the usage of chlorine results in hydrogen ions and these cancel out forming water: OH- + H+ --> H2O So the bottom line in an SWG pool is the following reactions: 4H2O + 2Cl- --> 2HOCl + 2OH- + 2H2(g) 2HOCl --> O2(g) + 2H+ + 2Cl- --------------------------------- 2H2O --> 2H2(g) + O2(g) 6H2O + 3Cl- --> 3HOCl + 3OH- + 3H2(g) 2NH3 + 3HOCl --> N2(g) + 3H+ + 3Cl- + 3H2O ------------------------------------------ 2NH3 --> 3H2(g) + N2(g) So the bottom, bottom line is that the net result in an SWG pool from the creation and usage of chlorine is that water is split to produce hydrogen gas and oxygen gas or that ammonia (urea) in the water is broken down (oxidized or "burned" in some sense) to produce hydrogen gas and nitrogen gas. These net, net reactions, as you can see, are neutral. At this point, you can now talk about the source of rising pH being the outgassing of carbon dioxide from the pool. You should explain that pools are in essence intentionally over-carbonated, similar to a lovely tasty carbonated beverage! This is done when you initially added baking soda or sodium bicarbonate to your pool (it also happens when you add some pH Up products that have sodium carbonate). The purpose of having extra carbonate in your pool is to act as a pH buffer and to provide carbonate ion that, along with the calcium you added to your pool with calcium chloride, saturate the water with calcium carbonate so that this compound does not get dissolved out of plaster/gunite/concrete/grout. If too saturated, scaling would occur essentially precipitating calcium carbonate on to pool surfaces. Also, the calcium carbonate tends to form a thin film layer on metal surfaces that help reduce corrosion, though pH is a much more important factor for metal corrosion. Pool water chemical balance attempts to keep a balance between corrosion and scaling. The downside of having a pool over-carbonated is that there is more carbon dioxide in the pool than in the air so there is a tendency for it to outgas. When this occurs, the pH rises while for technical reasons I won't get into here, the Total Alkalinity (TA) remains the same. If you then add acid to restore the pH, you lower both the pH and the TA with the net result of having TA get lowered -- which makes sense since TA is partly a measure of the amount of bicarbonate in your pool. The carbon dioxide outgassing, and therefore the rise in pH, is increased when the TA is higher, when the starting pH is lower, and when there is more aeration. So the easiest ways of reducing this rise in pH are to lower the TA, keep the pH higher, and reduce aeration (waterfalls, spillovers, etc.) including using a pool cover. For an SWG pool there is another way, in addition to lowering TA, that can help reduce the pH rise. That is to add an additional buffering system to the pool that is also an algicide that will cut down chlorine consumption. Adding 50 ppm Borates (from Borax, the 50 ppm technically being Boron) to your pool will add additional pH buffering capability so that you can keep the carbonate part of the buffer lower. To compensate for water balance, you need to keep either your calcium level or your pH higher (or both). The algicidal properties of the borates lower the consumption of chlorine which will let you lower the output of your SWG which lowers hydrogen gas production so less aeration so less carbon dioxide outgassing and less pH rise. Whew!"

I like Neilaz's suggestion but would recommend you do it in the bath tub instead as it would take a lot of pool salt to be added to your pool--a waste of money just to "check it out." Go to Lowes or Home Depot and get a bag of pool salt less than $10, put two cups in your filled bath tub, sit in it and see how you like the feel on your skin. It's also exactly as Scrapula described. However, I personally don't like water softener for the house because I can't get that "clean" feeling after after a bath or shower--it feels to me like I have hair conditioning on my skin. But salt water for the pool is a whole different story, I do like the softness of the water and because I'm not using soap with the water I'm not expecting that squeaky clean feeling like I do when I get out of the shower. On a different note, some people do not like the taste of salt water in their pool. There was a post on how salty the water is with a SWG and it varies between "no taste" to some salty taste. Ours is slightly salty. My 7 year old son and 4 year old niece are still not used to it so they will gag/throw up if they happen to gulp in some water (they are both in the learning to swim stage.) Something to think about also.

I believe if your water is too hard, the ionic conductivity can become a significant portion of the normal conductivity contribution of Na+ and Cl- ions and there is no way for the system to differentiate between the two. If you have a water softner in your house, you can siphon water off the softner to partially fill your pool to lower the contribution of Calcium. I have seen some TV advertisements about a new type of softner that looks very interesting and easy to install but have not looked into it further.