Yes you should, during my shock process this spring I was amazed how fast the bleach was used up
I miscalculated and overdosed, my fc was 26
The next morning it dropped to 12
So yes I would check it

If your shocking print out the pertinent sections of pool school, everything you need is there. You'll need to do alot of testing and adding of bleach.

PS, don't worry about the "complexity" of testing, I'll bet by the end of the shocking you'll have it all down, in a month or 2 you'll be a pro!

Should I retest everything or just the FC and PH? Thanks!

Once you start the PROCESS of SHOCKING your pool, you will just need to test FC and CC. You can disregard pH when FC is above 10, which it will need to be while you are shocking.

thank you!

Still showing no or very little chlorine...I'm getting so frustrated!!!!!

What number is considered "shock level"?

Could you post a complete set of water test results and describe what the water looks like? That may give us some hints about what is going on.

Shock level depends on your CYA level. There is a chart in Pool School showing shock level for various CYA levels.

CYA is 60 and FC is 2...getting dark now, so I give up tonight. I've added and added bleach...might just use the shock it tomorrow... I took the pump off the timer so it can run all night and I'll start again tomorrow. This stupid pool is not going to win!!! Grrrrrrrrrrrrrrrrrrr..........

All the shock it will do is raise the FC possibly to a level way to high with potential damage if you do not dose correctly. And it will add either CYA or CH to the pool.

The chlorine is the same no matter where it comes from.

Hang in there.

Posted with Tapatalk ... sorry if I sound short ... hate typing on phone

OK this morning test results are: FC 1.5 PH 7.0 Alk 40 CYA 100. Should I add baking soda or borax? Pool calculator says either or....confused about that. Pool water is still cloudy.

It is unlikely your cya went from 60 yesterday to 100 today unless you added liquid stabalizer (cya) or put in a bunch of dichlor/trichlor? Did you do either of these?

If your cya is 100, then you need to do a drain/refill, but lets discuss your test method first.

When you tested last night did you have plenty of light to do the test? We typically recommend during the day, sun out, with the sun at your back? If you do not have those conditions, then you will need a fairly bright light inside.

Your TA of 40 is low, is this the first time you have measured it? If you are confident in the value, then use baking soda to raise it to 60 ppm. One hour after adding, recheck TA and ph and post your result.

This pool is over 13,000 gals. It's a 15 x 30 oval above ground. Draining is not a real option right now. I added nothing but bleach yesterday and I had my back to the sun when taking the tests. I will go do the CYA test again....I'm already low of the cya test liquid..can I add borax instead of baking soda? I'm out of baking soda now....going to retest the CYA. Thank you!

Same results......100 CYA. I'm really getting discouraged now....

With the CYA test you can redo it without reusing the solution, just pour it back into the mixing bottle and then do the test again. (do NOT pour it back into the reagent bottle)

With a CYA of 100 you will need a much higher FC level to shock. You are probably going to need to drain by 50%, but that will make shocking much easier.

Not to trivialize your efforts, but I think you need to slow down, read and re-read all pertinent sections of pool school (if you ask about CYA vs shock level it means you didn't read that section of pool school, there's a chart there). Understand the process first and then execute it.
Your going to have to raise the chlorhine level to shock level and then hold it there until all the bacteria is killed off, this may take some time, then your levels can come down to non-shock levels and be held there quite easily.
This means your going to be adding ALOT of bleach and doing ALOT of testing, there's no way around it, except perhaps pay someone to correct the problem or drain/clean your pool (and personally I'd rather shock than drain/clean a pool).

Just keep those levels up, you'll get there!

You should never fully drain an above ground pool. From a cost/benefit perspective it might be cheaper to drain half the water. Your CYA could be higher because the test only goes to 100. Even if the cost is at a break even point, it's still better to drain. If you slip up once and have to shock again, it's going to require a lot of bleach to shock once more. It's not impossible to maintain a high CYA pool but if the costs of draining is the same or lower than the cost of bleach it makes much more sense to drain. Much less headaches too.

Finally getting it under control now. FC is 4 and CC is 0. Only thing up is TA....Pool is looking better, just a little cloudy now, but you can see the bottom good now.

You are not done with the shocking process, so don't let you FC drop much below 25 ppm (poolcalculator and 100 cya). 4 ppm FC isn't even enough chlorine at 100 ppm cya for normal pool use (8 ppm minimum) let alone when shocking. You are not done until you simultaneously pass all three end of shocking criteria (see my sig).

I think you do not understand the shocking process. Please re-read then ask us what questions you have so we can be on the same page. http://www.troublefreepool.com/pool-school/shocking_your_pool

As mentioned before 100 ppm is very high and it would be best if you do a partial drain/refill. If you still believe that is not an option, then you will need to be very attentive to the process or your pool won't be algae free.

I am still shocking and CYA is going down also. I'm just saying I think I'm getting there now!!!