Another cloudy pool

lmannyr · Postby **lmannyr** » Fri 16 Oct, 2009 08:14

FC 20
CC < OR = 0.5
PH 7.2
TA 100
CYA 80

My Hayward cartridge pump has been running 24/7 for 2 weeks now. Changed out the 1 year old cartridge filter for a new one yesterday. I just started to use a the Taylor K-2006 test kit 3 days ago.

The pool was green 2 weeks ago and cleaned the filter twice a day (very filthy) for a few days. Then the pool was just cloudy and the filter looks clean every time. I clean it at least once a day just in case there are white particles building up. There isn't a pressure gauge on the cartridge. I want to add one though.

Pool has been at shock level (20 ppm) for at least 3 days now. Do I keep chlorine at shock level until clear?

Is 20ppm FC safe for my walmart pool?

Where can I get the gauge to add to my filter?

Postby **chem geek** » Fri 16 Oct, 2009 09:56

The shock level at a CYA level of 80 ppm (which is high and probably the original source of your problems) is closer to 30 ppm, but 20 ppm will work and just take longer to clear the pool. If your circulation in the pool is poor, then you could spend more money if you are impatient and use a clarifier or a flocculant (for the latter you would need to be able to vacuum to waste). Read Defeating Algae in the Pool School and read the other articles about how to maintain your pool so you avoid the continual increase in CYA from stabilized chlorine products.

If you want to continue to use Trichlor or Dichlor stabilized chlorine, then you will need to use algicide or phosphate remover at extra cost and even then these will only work up to some point. Either that or you will need to regularly dilute the water to lower the CYA level. The amount of "active" chlorine (hypochlorous acid) that kills algae is proportional to the FC/CYA ratio and has nothing to do with FC alone. This is why higher CYA levels require higher FC levels to continue to kill algae faster than it can grow.

lmannyr · Postby **lmannyr** » Fri 16 Oct, 2009 15:09

My pump runs at 2400 gallons per hour. It turns my pool over in 2 hours.

Drained half of the pool water today and refilled in an effort to reduce the CYA level. Surprisingly, the CYA level is now 90! Why Would this happen?

Postby **chem geek** » Fri 16 Oct, 2009 22:03

Most likely measurement error. Are you testing this yourself? If tested at a pool store, they often don't do such tests very well, especially near 100 ppm.