Out of curiousity, I checked with the unicel website, and acording to that information, a mild acid soak is advisable after the initial cleaning proceedure, if calcium buildup is suspected. The initial cleaning proceedure is to first soak with a degreasing agent, rinse, then soak in the mild acid. One thing that does bother me is the Unicel site says a test of wether or not to use the acid soak, is to put several drops of undiluted acid directly on the filter media! Wait, question here... if a dilute solution is so bad, why the hel...ahem, heck would you put undilute acid on it at any point? BTW I never did find the section on the site stating that the acid will drive the "gunk" into the filter perminantly...
The site mentions the tried and true method of how people washed D.E. grids (diatomacious earth grids). It cites that the reason those grids held up over pleated cartridge filters is due to the protective D.E. media that coats the grids. Personally I can't see this as being a valid statement, in that when you clean a D.E. filter grid, you remove all traces of D.E. media prior to the soak. Also, the acid soak for these filters is generally much stronger in concentration than the simple cartridge filter soak. I have a D.E. filter on my pool, so I know.
I think what the site is saying is that the traditional soak of muratic acid on a pleated filter will have harmful effects, over time, but only in that many people may be using the stronger concentration as used for the D.E. filter.
I also believe that the degreasing agent (as mentioned) may help dislodge some fatty solids from the filter, but in reality the spray down of the filter is what is doing most of the work.
Perhaps I should elaborate on the cleaning procedure I STRONGLY recommend and live by:
First (and this is true with ANY cleaning method) thoroughly spray the filter with plenty of water to remove any loose contaminates. This will dislodge any foreign particulate matter, including oils.
Soak filter in the muratic acid and water solution
Spray off filter as in the first step
Reinstall and use as normal.
FYI my filter is 3 years old, looks as good as new, works as good as new, and this is the only method I've ever used on it.
Now, regarding the chlorine....
Chlorine will dissolve any organic compound if left to soak long enough. It is a base chemical (having a PH lower than 7). All base chemicals have the properties to dissolve organic compounds. Lye is Sodium Hypochlorite, and is essentially a super strong bleach, based on the same compund of chlorine. In the food industry it is used literally to dissolve remaining food particulate from machinery. Your crystal Drain-O is the same thing, for the same reason.
That said, chlorine soaking will dissolve organic compunds from a filter, including organic oils. The problem is it won't actually clean the filter.
Acids are used to dissolve petroleum or other non-organic compunds. Your driveway cleaner is acidic for this reason. Acids are also used for that purpose in the food industry for similar reasons.
This points out that while filter cleaners (as stated for such purpose) claim that their product is best for cleaning filters, if a person looks at the acid content, they will see that the filter cleaner is based on acid. Acids and soaps (bases) are not compatible, will react to one another, and neutralize into simple salts in the end. For that reason you won't ever find a soapy filter cleaner.
Man, I am really rambling on way too long on the science of this crap... take it from me, pageup, and others in the know and in the practice of use, that simple muratic acid will do the job nicely.
