Cleaning the filter -- weird water color

[trclac]

I have an inground 17,000 gallon pool, with a canister type filter that contains 4 cartridges (cartridge number 460, I think). The other day, I drained the filter, and all the water was chaulky white. I unsealed the filter and removed the cartridges. They were full of a white, chaulky substance that resembled extremely wet mortar. This is a first in my three years of owning the pool. Usually, the filters are just "dirty", with dirt, trapped bugs, grass clippings, etc. I can't imagine what the white substance was -- I even took a pressure washer to the filters and it took a good hour to clean the cartridges with the pressure washer. Any idea what could have caused this?

As for sterilizing the pool, we use the in-chlorinator pucks (about 3 a week, given Houston weather) along with Zappit; I put about a cup of Zappit in the pool every other day. Could that be the cause? Too much chlorine trapped in the cartridges? If that's not it, I don't know what is, since there is no construction around here which would blow dry cement powder or mortar into the pool.

Thanks for any ideas.

 

[Suziqzer]

It's not likely chlorine... pucks are either combined w/stabilizer or calcium both of which will build up in your pool and cause trouble. Check your containers and see what you are adding to your pool.

People here don't typically use pucks on a regular basis because they can cause problems over time that can only be resolved by partial draining of your water to reduce amounts.

Most likely you have a build up of calcium in your pool but without seeing your ingredients hard to say for sure.

Get a full set of test results and that will help too. It is recommended that you get a good test kit and do your own testing because pool stores are notoriously unreliable.

 

[Poolschoolgrad]

Zappit is calcium hypochlorite so the white chalky substance may be calcium scale.

A complete set of water tests should reveal the cause.

Switching to liquid chlorine every other day in place of the zappit would add a comparable amount of chlorine but not add calcium.
You also won't need the pucks.

There are a lot of great folks on this forum who can help you get your water into sparkling condition, but accurate water tests are required.

PSG

 

[Bama Rambler]

x 3 for a full set of test results and how you got them?

 

[JamesW]

Definitely need a full set of test results.

If the cal-hypo is being added through the skimmer, then there could be extra residue that builds up beyond what would be expected just due to the general water chemistry.

Also, if anyone has added DE at any point, then that could explain it. (DE is not normally added to cartridge filters, but a manuals few suggest it).

 

[trclac]

Thanks, all. Sounds like calcium, which would make sense. As for the pucks, I learned my lesson. I've had to drain the pool twice because they added too much stabilizer. I've only used some lately because my stabilizer was reading around 30, and I thought I'd raise it some under this Houston sun. But I will get a full set of test results tomorrow.

Thanks!

 

[trclac]

Almost forgot -- and don't laugh too hard. I've only used Zappit and the pucks for chlorine. I've asked the pool place about liquid chlorine, and they said it doesn't exist for pools. So are you talking about everyday bleach, like Clorox, and if so, about how much do you use per week? Thanks!

 

[chiefwej]

10% chlorine is available as a pool supply. Your local Walmart will even have HTH brand in aa box with two one gallon jugs in it. Household bleach is the same thing, but 6% chlorine and it's usually a cheaper way to buy chlorine.

 

[trclac]

Thanks! Again!