Re: cartridge filter maintenence

Originally Posted by
cscannon
- I have a Pentair Clean and Clear Plus cartridge filter. The owners manual states the I should "introduce 3/4 pounds of DE per 100 spuare feet of filter area." However, in searching the forum, I haven't seen anyone else recommeding this. The manual states to do this "for first time operation on new pools". It is not clear to me if I must add more DE everytime I clean the filter or just when I replace the filters.
My understanding is that is just the first time with the first cartridge to help remove any construction dust that might be in the water.
- A pool book that I bought recommends soaking the filter in dilute solution of trisodium phospate and muriatic acid. I am reluctant to do that as the owners manual says to just use plain water to wash off the cartridge. Besides which, it is not clear to me that any additional soaking is necessary.
Soaking is a good idea yearly. Use TSP or if that is not available in your area because of the phosphates (it's been banned im most states) then use an automatic dishwasher detergent powder like Cascade or Electrosol...they are mostly TSP. Use one cup for every 5 gallons of water. Do this before acid washing or any orgainics on the filter will harden into a cement like mass and you will need to replace the cart. Only acid wash if there are calcium deposits on the cart after soaking in TSP. Unicel, one of the largest manufacturers of OEM and replacement carts has these instructions for cleaning the carts
http://www.unicelfilters.com/pool_ow...rine_users.asp
They also advice against using DE with carts but suggest that a cellulose DE replacement is ok to use.
- Finally, please indulge me in what might seem a stupid question. People say that their pool is crystal clear. My pool is too... until you turn on the light at night. Then the water seems full of particulate matter. Is this normal?
Carts filter to about 20 microns so you might notice some cloudiness with the lights on at night. Carts filter better than sand filters, which only filter to about 60 microns. If you want 'polished' water you need a DE filter which will filter to about 6 microns. IMHO, Carts are a good compromise between good filtration and ease of use/run time between cleanings!
Thanks,
Steve
Hope this helps.
Retired pool store and commercial pool maintenance guy.
Bookmarks