First time shocker-needs guidance


Jun 25, 2010
Hi all
Lots of rain lately. Pool sets near a tree; fairly diligent in keeping debris out. Pool in about a month. Got milky cloudy. Then cleared up a bit with extended swg run. still not crytal-clear but can see bottom of pool. floating slimy transparent jelly-like substance floating in pool. Fuzzy, dusty matter in pool as well.

My plan is to shock the pool according to the following information. I am new at this and need some assurance so...let me know what you all think.

Note: I have a limited reagent test kit. I have a TF-100 XL on order; it should arrive in 3-5 days.

1. Free CL, CC, CH, CYA-unable to determine with kit i have.
2. PH =7.6
3. TA=160+ (ph is ok and no calcium scaling so i am leaving this alone)
4. Total Residual Cl (both CC and Free)-between 1-1.5 (in range per my test kit). This test appears worthless.
5. CYA estimate-8ppm (based on .1kg cyanuric acid in 12430 liter pool, per mfg specs). This seems low based on TFP suggested ranges but I wouldn't be surprised if my math is in error.
6. Based on my CYA estimate (8 ppm), I determined the shock target to be 12. This target was determined by utilizing the 2nd row of the following table i found in TFP:
Stabilizer . . . . . . Min. FC . . . . Max FC . . . 'Shock' FC
=> 0 ppm . . . . . . . 1 ppm . . . . . 3 ppm . . . . 10 ppm
=> 10 - 20 ppm . . . . 2 ppm . . . . . 5 ppm . . . . 12 ppm
=> 30 - 50 ppm . . . . 3 ppm . . . . . 6 ppm . . . . 15 ppm
=> 60 - 90 ppm . . . . 5 ppm . . . . . 10 ppm . . .. 20 ppm
=> 100 - 200 ppm . . . 8 ppm . . . . . 15 ppm . . .. 25 ppm
7. Based on the pool calculator for FC (current=1.5, target =12), I plan on adding 72oz of 6% bleach to attain shock at 12ppm. The current value used (1.5) is my best guess based on the Total Residual CL value noted above.

Any advice would be appreciated. Thanks in advance!


TFP Expert
LifeTime Supporter
In The Industry
May 20, 2007
SWSuburban Chicago, IL
Would u consider draining and starting over? :shock:

I only suggest this cuz Intex filters are mediocre at best for daily use - when a problem develops it's usually better just to drain and start fresh.

If you don't want to drain, then yes, shock as you determined - but change the filter every 2-3 days until it's clear - yes toss it - and then once the pool is clear, and you have the good test kit and can determine the FC is holding overnite, the filter can last 1-2 weeks.

Sounds like you have a handle on the process :)

When you have things cleared up you want to get that CYA level to 60-80 and then maintain the proper FC level to prevent the cloudiness again...

Water Balance for SWCGs


Jun 25, 2010
Appreciate the response. I have never been one to walk away from a fight and, given your confirmation of my approach, i am leaning towards shocking and watching clarity (until get new test kit). Once again, appreciative of your time as, based on my review of this forums threads, you do appear to know what you are talking about.


TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
Silver Spring, MD
With a small pool draining and refilling is fairly easy. Plus, the Intex filters are terrible at filtering out all the debris you get when fighting algae.

If you do plan to continue without draining, you should bring your CYA level up a bit. It is very difficult to maintain a proper shock level when the CYA level is so low and you are losing all of your chlorine to sunlight. Also, shocking is much simpler when you have a proper test kit with a FAS-DPD chlorine test, so you can distinguish FC and CC from each other.


Jun 25, 2010
I have added CYA and Bleach and the change is remarkable. The pool looks good. Wish i had the TF-100 XL right now. Thanks everyone. Will give post mortem.