Calcium Hypochlorite doesn't fully dissolve

[dgcpe]

Whenever I use calcuim hypochlorite shock i get a fine sediment on the bottom of my pool that does not get trapped in the filter. I vacuum and its back the next day. If i want to get rid of it, I need to vacuum to waste which is a complete pain. I've tried clarifiers and that does not seem to help. Does anyone else experience this issue and if so, how do you deal with it?
Thanks for your help.

[waste]

Welcome to The Forum!!

It's the nature of the beast

I don't know what kind of pool you have, nor how you add the cal-hypo.

I do know how to add it without the results you're getting.

Add 1 cup of cal-hypo to a full 5 gallon bucket of water and use a stick or broom handle to mix it. Slowly pour the chlorine water to the pool by walking it around the perimeter. Watch the solution you're pouring in to see when sediment is in the mix. When you see sediment - STOP pouring and slowly add fresh water to the bucket and stir it again for a minute. Resume your pouring where you left off. When you see sediment pouring out of the bucket again, stop pouring and ditch the rest of the mixture.

The last bit of sediment is undissolved calcium carbonate or calcium products and is probably what you are seeing on the floor of your pool. However, if the calcium levels in your pool water are moderate or low, this sediment will dissolve eventually.

Tell us more about your pool and how you add the cal-hypo and we may come up with more info.

[dgcpe]

Thanks Ted. I figured that would be the answer (have heard it before). My pool is a 33' round, Pool Frog mineral/chlorine feeder, Pentair Clean & Clear 175 filter, 1 1/2 HP 2 speed pump, Raypak A406 gas heater, wife, 4 kids, dog...oh, sorry.

Anyway, this is season #7 for the pool and this issue has been prevalent since last year. I typically broadcast the shock over the pool. I opened Sunday and the cal hypo i used settled to the bottom. Shouldn't that filter out eventually?

I shocked yesterday using the method you described (mostly - I added 2lb to the 5 gallon bucket) but have not had an opportunity to see if it settled as the kids hit the pool right after school and its all stirred up. It is pretty cloudy though.

Other info from tonights testing, Chlorine about 0.5 with Frog set at 3 (i usually run 2.5), pH 7.6, Alkalinity 140.

Thanks again, any other thoughts would be appreciated (alternative shock chemical perhaps?)

Doug...

[JimK]

I noticed the same thing when I shocked with cal hypo. Since I wanted to stop adding calcium to my vinyl pool, this year I just end used plain bleach. No predissolving necessary and problem solved.