One way to save money on filter cleaning chemical is to buy or make a filter cleaning flask. I purchased one online, but it would be easy enough to make your own. The one I bought is simply a 16 inch length of 6 inch diam. PVC pipe with a cap on one end. This way I only need about a gallon and a half of cleaning solution instead of 5 gallons. You can find several examples online by searching for "spa filter cleaning flask"

---[BTW I never did find the section on the site stating that the acid will drive the "gunk" into the filter perminantly]

Did you not read all of my excerpt of 6: ?,
WARNING: Failure to remove all oils and
cleaning solution before acid soaking will result in a
permanent restriction of water flow and cause premature
cartridge failure.

---[The site mentions the tried and true method of how people washed D.E. grids (diatomacious earth grids). ]
Why even use any cleaning products for DE, its the DE that traps ths contaniments from the pool, hose that off and your done.

---[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.]
Thats like saying, if I use enough water, i can just rinse my laundry, never needing to use a detergent

---[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]

Wish you had a cartridge filter, and i was the guy u were going to be buying filters off of, if you were, and i was, i'd see you about every 2-3 years or quicker than that.

---[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.]
again your using DE filter, not a cartridge, hose it off and your good as new.

[Now, regarding the chlorine....[/quote]

only way for some people to learn is the hard way, good luck.

spec

PS: first off i recommend you get an actuall filter cleaning solution for cartridge filters, even if you do not have alot of minerals in your water, some minerals still get trapped by the filter, i recommend BioGuard Strip Qwik, as it is mainly targeting oils and some mineral deposits. this is a good cleaning solution, if this is unavailable and other dealer brands are not available, then i would recommend TSP, but only the "real" tsp in granular form, not this phosphate free crap.

I cleaned my filters in muriatic acid and it made my Tri-x filters start to come apart. My dealer recomended it. I had to call watkins and they gave me new filters my dealer would not do eneything. Watkins said never use muriatic acid.

If you used too strong of an acid to water ratio, that would cause a lot of problems. Watkins is cheaper for a reason... Good filter cleaning solutions are acidic by nature. Muratic is a bit stronger so you need to dilute it properly.

The general culprit clogging spa filters is body oil. That's why surfactant type cleaners work best.

Leave the acid for pool filters. You should NEVER need an acid bath for typical hot tub filters.