Can not get chlorine level up

[Jrminde]

Over the last 72 hours I have added 8lbs of Leslie's shock multiple chlorine tabs and I can not get the chlorine level up in my pool. I have stumped the folks at Leslie's. The following are the results of my last water analysis:
Free Chlorine = 0
Total chlorine =0
Calcium Hardness= 300ppm
Cyanuric acid=70ppm
Total alkalinity= 110ppm
PH =7.8
Copper=0
Iron=0
Total dissolved solids =900
Phosphates= 100ppb
Nitrates= 5
When I add shock or chlorine the water gets cloudy but quickly clears with the filter. Pool is approximately 30,000 gallons....any ideas on why I can't get the chlorine up?

 

[duraleigh]

Welcome to the forum. :lol:

any ideas on why I can't get the chlorine up?

Yes. Chlorine is a consumable item that must be constantly replenished. Yours is being consumed at a VERY fast rate because you have organics (algae) growing in your pool.

read "The ABC's of Pool Water Chemistry" up in Pool School then read "How to Shock Your Pool". If you follow those articles precisely, your chlorine consumption will be drastically reduced.

You didn't ask but that powder you are getting from Leslies is clouding your pool by adding Calcium and you can never get rid of it unless you drain some water. 300ppm is fine now but you really don't want any more. Learn how to shock your pool using bleach.

 

[JasonLion]

Welcome to TFP!

[shock:2fq0896l]You need to properly shock the pool. With CYA at 70 shock level is around 28.[/shock:2fq0896l]Your 8 lbs of powder would have raised the FC level to about 23 once. You need to raise FC up to about 28 and hold it there, which will take far more chlorine than you have used so far.

The other option is to replace some water to get CYA down before continuing to shock the pool. If you have a SWG, it might be best to leave CYA where it is. But if you don't have a SWG, lowering CYA first is probably the best approach.

 

[Jrminde]

Thank you for the prompt replies....some additional information...I had no problem with my chlorine levels 2 weeks ago before leaving on vacation. Can algae happen that fast? Also I had algae when I opened the pool but killed it.....the pool is "blue" with no signs of greenish hue. While on vacation I had my pool filter replaced....could this be an issue? Any tests you can do to detect levels of Algae. I have had this pool for 7 years with no water issues but this year has been problem after problem ( algae, nitrates, filter and now chlorine)
I will give the above advice a try but just wanted to share some more background....

Thanks

 

[duraleigh]

Two things consume chlorine in a swimming pool....sunlight and organics in the water. Given the proper CYA level, sunlight loss will account for usually around 2ppm or so. If you are consuming way more than that, you have organics (algae) in your pool.