Pentair M-320 filter for in ground swimming pool?

Salt water pool by Pool Pilot,excessive calcium particals in bottom of spa,a lot,same in pool but can't because of volume of water 22000 gallons.Clean filters @salt cell every 90 days.Calcium coming from cell.Why isnt filter catching these particals?Something cracked or maybe o-ring leaking inside filter housing?Can't see anything really wrong,system 9 yrs old.Water chemistry perfect crystal clear water.These calcium particals r getting by filter.Thankyou so much for any advise pool companys here don't no squat.Joe Palm Springs Ca.
Scubabob u made some interesting points,pool water isn't heated bout 54 degrees rite now and we have a automatic pool sweep.water does pass thru heater even if not on.Calicum hardness fine bur don't remember what it is.Sand change like in dc?filter has cartriges,also water changed every year.Cell does reverse polarity,2900 ppm salt.bet cell is the problem can't believe pvc lines doing this.ty so much 4 your interest
Gosh I am bad at this,failed to mention we live in the desert,blowing sand and grass clippings from the gardners.Water temp changes with the weather,summer time can get 226 degrees with water twmp at mid 90's.We never use spa so heater isn't an issue acts as a water feature flowing into pool.We have a pebble sheen pool.I wonder if bottom manifold inside filter housing is cracked?When I take a sample from cell plates,carefully,then let them dry,they are the same as FLAKES not dusty in spa when dry.I don't no of a person who doesn't change there pool water every 2 years.Thanks

Comments

scubabob says:

February 16, 2010 at 12:18 pm

You did have your calcium hardness checked and how warm are you keeping the water? It is entirely possible to have a calcium build up in both the plumbing AND the heater, then have those particles eject out the returns. It is after all, past the filter and I assume that filtration equipment is doing double duty for both pool and spa.
I question the operation of your salt system though. Most are supposed to be self cleaning in that they reverse polarity at intervals to shed any minerals or metals that are clinging to the plates in the cell. If you’re having to manually clean every 90 days because they are choked up, something is amiss there in either your chemistry, the cell or both. The Pool Pilot system is not one that is popular here so I’ve not ever come across one but they all operate on the same principle and have similar features. I really can’t trouble shoot any codes it displays without a manual.
Question here: You say the particles are getting past the filter. Are you saying that when you vac…they just blow back out the returns as you vac? You’re not very clear there. Until I know the answer to that I doubt very much it’s a filter issue, although if you haven’t done a sand change in the last 9 years, you will be due for one soon. If the water is clear and sediment free, that usually indicates the filter is indeed working and not channeling through the sand bed to the laterals because of calcification.

Edit, ok, the Petairs around here are all sand, I just assumed without looking it up. No holes in the elements, you can rule that out as a problem. Especially with a cart filter. They filter down to 20 microns. Calcium is bigger than that.That water is 54 F all the time? You have a spa there and yes..pvc plumbing can collect calcium build up, especially at fitting joins.
About your cell: Salt level sounds fine, most units by any manufacturer run between 2500-3200 ppm. If the polarity is reversing it should be self cleaning itself. That shouldn’t be the issue there then.
Let’s clarify this. What leads you to believe that this is indeed calcium? Is it flaky or is it dusty? I’m also questioning why you changed your water out every year? The norm is to either wait until the TDS (total dissolved solids) peak or every 8 years or so, whichever comes first for a concrete pool ( this is concrete, correct and if so..is it by chance painted?) Did you dump because of a TDS issue every year?
One last thing I can think to ask with what I now know. Are you using any additional sanitizers in that pool such as adding the occasional dose of calcium hypochlorite?

2nd Edit:Every two years dump? That’s still extreme unless for a TDS issue and VERY expensive. I wouldn’t expect filter damage other than freeze damage or from a solid smack. The plastics in use for pool equipment are pretty tough and with a cartridge filter, the water flow is from out to in. You’d be able to see any cracks at the bottom where the element mates with the bottom of the filter body.
I’d actually be taking a sample of that "white stuff" in for examination. Calcium will flake as a rule right off the bat, not as it dries. It forms as a crystal and doesn’t congeal. If you leave the pool alone after a vac…does this stuff come back gradually, immediately or does it show up after some other event like a temperature change? Where in the pool does it show up? Below the returns or everywhere? And..as I asked before, do you use any other additional sanitizer in that pool, like toss in the odd dose of calcium hypochlorite?