Typical garbage science from Aqua Magazine...one thing to remember is AM is a trade rag for the pool industry and they often let industry insiders write "feature articles" which are almost always biased to their point of view and/or the product they sell.
Let me rebut a few points -
1. Galvanic corrosion - well, I'll give them points for at least showing a Galvanic Corrosion Chart and spelling the word "galvanic" correctly
They are totally WRONG when it comes to SWG's and galvanic corrosion. First off, the titanium metal plates in an SWG
are coated with a layer of mixed metal oxide catalyst (ruthenium m oxide and iridium). So, there would be almost no galvanic couple created in that configuration. And, even if titanium is directly exposed, titanium metal is too reactive and forms a passive and adherent titanium oxide layer. There is simply no meaningful way for a Ti/Cu galvanic couple to form....oh, and guess what, the inside of a heater core, the "Copper coil" is actually copper with a passivation layer of copper oxide and calcium scale on it. So again, not really going to find a galvanic effect there.
2. Bad Salt - yes, you can get some impurities in salt. TFP users commented about 2 years ago on Clorox brand pool salt leaving metal stains. They were iron stains and the likely culprit was sodium or potassium ferrocyanide which is often found in salt as an anti caking agent. There can also be other iron impurities and dirt as well in salt. If one uses pool grade salt from a pool store, the purity is higher but you pay a bit more. But, even if one uses the lesser grade of water softener salt, who cares?? Simply add the salt and brush away any dirt or stains that might show up. It's certainly not a reason to abandon an SWG.
3. Sequestrants - Hmmmm, the guy making the comment is the head honcho of SeaKlear....a major manufacturer of sequestrants! I hate to burst their bubble but ALL FORMS OF CHLORINE will oxidize and breakdown sequestering agents...it's called oxidation. Doers this happen faster in an SWG cell....maybe, maybe not, it depends on the type of sequestering agent used. HEDP does breakdown upon exposure to chlorine but PBTC has a 4X lower rate of oxidation from chlorine. And, as TFP states, why does anyone need to use these chemicals regularly?? I run and SWG pool with no staining and no sequestering agents at all...and I have done some for almost 6 years now. Clearly there are other culprits to blame.
4. FC level inside a cell - the article states that the FC level inside as cell can go as high as 50ppm....I don't how their calculating that number but it is most definitely not that high. For example, my SWG theoretically produces 1.4lbs of chlorine gas per 24 hours of run time at 100% output. So that's roughly 0.06 lbs of chlorine gas per hour of run time at 100% output. In order for an SWG to operate, water has to flow through it and most SWG's have a lower limit of 15GPM. So, in one hour of operation, 900 gallons of water flows through the SWG cell. If one adds 0.06 lbs of chlorine gas to 900 gallons of water, you get an increase in FC of ~8ppm. My cell holds about 40 fluid ounces of water. So, if you assume the FC is evenly generated in the cell and dispersed evenly through the total volume of water flowing through it then, at any given instant as water is flowing through the cell, -
8ppm * (40/(900 *128)) = 0.0027ppm FC
So, if they think the FC inside the cell while it is running gets to 50ppm, then they are inhaling way too many chlorine vapors OR they failed basic high school math & chemistry.
