New to pool care, new house / pool for me...

[some_finger]

Folks,

I recently bought a place with pool. I have, a new Taylor K2005 complete test kit. The pool started out way too high in CYA (prob between 150 and 200). I have done partial drain and fill twice and CYA is down to about 45. So it is time to get going. The chemistry looks as follows:

FC .5
TC .5
Ph 7.7 (some place between 7.6-7.8)
CYA 45
TA 110
CH 60

Looking at pool calculator It seems I should be adding about 182 oz of liquid bleach (6%) and at some point deal with CH. Is that about right? What is the difference between adding bleach and shocking the pool? That is ... should I be adding substantially more or some powered shock product at this point?

I guess that the pool remains and will remain covered most of the time it is not used.

In case the sig. does not show it I have a 36k gal. in ground pool with a vinyl liner. Current tmp is still chilly I expect the pool water is no more than 55 deg F right now. Don't have a thermometer yet.

 

[RobbieH]

Your CH is good for vinyl as best I can tell, but let someone else chime in too.

You can read Pool School in the top right for details on the shock process. Adding chlorine is used to maintain the pool, the shock process is to kill algae.

 

[JasonLion]

How does the water look?

CH is fine where it is.

Shocking means maintaining a higher than usual chlorine level to kill algae or burn off organic debris in the pool.

We don't generally recommend using powdered shock, except in unusual situations. It doesn't matter where the chlorine comes from except that some forms of chlorine add other things to the pool that you don't want.

 

[some_finger]

Water Clarity looks fine right now. I was bit concerned as the water looks a ting green to me. but That might be the color of the liner coming through I don't know. a week a go when I started the drain / fill cycle the FC / TC were good (don't remember the numbers now) but now with the over 50% water replacement to get the CYA down I am concerned that I need to do something before algae forms. I know that there are phospates in the water I don't know what the reading looks like. The previous owner was using a copper solution to keep that at bay. Since I have removed a bunch of water I have prob. reduced that a lot at this point. But I would rather keep it up with Chlorine than use that.

So do I understand correctly... if I shock with liquid Chlorine that over some time the unused / unnecessary Chlorine will largely off gas from the pool?

 

[RobbieH]

The chlorine will either be used up neutralizing organics, or will be eaten by sunlight.

 

[snewo]

Just an FYI, you mentioned a Taylor k2005 kit. I don't think this one can measure the chlorine levels needed for you to shock. If I understand correctly you will need the FAS DPD test (I think I got that right) to make that kit the same as a Taylor k2006 which is what is recommended.

 

[some_finger]

Alright... so I shocked with liquid chlorine yesterday. Yes the 2005 from Taylor does not show CH over 5 so I had to dilute sample to get a reading. Now about 24 hrs later I am still at over 10 ppm of CH so the question is how long does it take for the CH to come down? Also I was a bit concerned that bleach pH is high and I was trending to the high side anyway 7.7 pH (before I started) I am now at 8. So should I add acid now or wait until CH is down to reasonable?

 

[chem geek]

"CH" usually refers to Calcium Hardness. For chlorine, you want to right "FC" for Free Chlorine.

Don't worry about the high pH. The pH test won't be accurate much above 10 ppm FC anyway. The FC should drop if the water is exposed to sunlight -- at your CYA level it'll probably lose up to 50% per day if the sun is on the pool all day.

 

[some_finger]

Also about Calcium Hardness ... should I wait till the FC returns to normal?
I am getting conflicting messages about Calcium hardness and vinyl liners & heaters. Do I care that Calcium is low given I have a vinyl liner? How does this effect the fact that I have a heater?

Waiting for the sun in the Northwest is sometimes like waiting for Christmas... you know it is going to come sometime this year....

 

[JasonLion]

Neither the liner or the heater has any need for calcium. However, if the heater is new enough to still be under warranty, the warranty may require some particular calcium level.