always SLAM at opening?

[Maresa]

This is my third year at this whole pool thing. Each season I begin to figure things out, then it's fall and I forget EVERYTHING the next year!
The pool guys opened my pool and poured in 2 1/2 gallons of "shock". Now I wish that I had tested beforehand, but...
So after this "shock", my FC was 13, CC .5, CYA 0, pH blood red (couldn't get reading), and TA was 100. (Calcium 170 and salt 1200)
I started on the process of SLAMming, but did it all wrong when I raised my CYA too much... like to 55. When I went to see how much chlorine I needed I realized why you should only raise CYA to 30!
Then, I decided to raise my chlorine up to match the CYA, and checked the chart on TFP, but there are no numbers for salt water pools. I guessed I should go by the regular numbers. So I added more chlorine ... up to 15.
Then, I reread that you should first balance pH, but also that pH is inaccurate when FC is over 10!
Now I am rethinking ALL of this... and begging for help.
1. Do you always need to SLAM at pool opening? I am doing it wrong now (hit and miss) but the pool is clearing.
2. SLAM says that there can not be any loss of FC overnight, but I am confused because isn't there always a downward drift from a high FC level?
3. Very weird... my CYA numbers have dropped in the past 12 hours... like from 55 to 35. Is that possible or is it just my misreading?
4. Should I put in SOME acid to drop my pH. (Each year I have a HUGE problem, which I will need to ask about later) of constantly using acid, so I assume that I would have had to do this anyways (if I had tested before the chlorine).
5. Finally, how long should I run the filter for? (As in, should I be SLAMming still?) My husband is nagging that I need to give it a rest.
A HUGE AND SINCERE THANK YOU BEFOREHAND TO ANONE WHO TRIES TO HELP ME!!!!!!!!!

 

[Nectarologist]

1. You don't always need to slam. Especially if your water is clear (or even cloudy). I've never slammed even w black water (I let leaves fall in ). But listen to what advice is given by others here as far as slamming.
3. You must be reading the cya incorrectly. It wouldn't go down like that on its own.
5. Run the filter 24/7 until it clears; the pump can handle it. If it's not running you're not cleaning stuff out of the water. Also make sure to backwash as needed.

 

[woodyp]

NO....a SLAM is not always required at opening if it is closed properly and opened early enough. It is acceptable to pass a SLAM with an OCLT of up to 1 ppm of FC. Don't run the SWG overnite while doing an OCLT if at all during a SLAM. ph will read falsely high if your FC is 10 or higher. You should have done that before starting. Run filter until SLAM criteria are passed. It doesn't matter if yours is a salt water pool during a SLAM. The same chart applies.

 

[awtrizzle]

I’m sort of pre occupied at the moment but a few things on your SLAM.
Technically you aren’t supposed to have to SLAM every opening. They say that if it’s done properly, close when water temp is below 60 and open with the same thoughts, that your pool will still be clear. I have a mesh cover and mine is never clear no matter what.
You should run the pump when you’re adding chemicals and from what I do, for approx 30 minutes before after adding, and approx 30 minutes before a reading. During a SLAM you want to filter as much as possible so you will also need to run the pump to do that as well.
CYA can only drop with removing and replacing water. From what I’ve learned anyways. It can also be eaten by something else in the water but I can’t remember what that’s called. (Someone please correct me on this) I think ammonia but you would have seen that during the adding of chlorine because it will go away almost instantly. Your FC not being zero is a good sign of no ammonia. Not definitive though.
Not having an overnight FC loss is what you want to look for to see when the slam can be stopped. Along with a CLEAR pool as well as less than 1 on the CC reading. You will have an FC loss every time your chlorine is “working” to kill something in the pool. Yes you will lose FC overnight during the slam because it’s being “used”. When it’s clean, even if it’s a high FC, it will not go down overnight because it’s not being “used”. It would over time though with sun and other contaminants.

If you’ve already started the SLAM I wouldn’t worry about your PH level. You can adjust it later, or if you’ve accidentally let the FC level go down. They say to adjust it prior to the SLAM because you shouldn’t be able to get an accurate reading during the slam. Since you’re supposed to keep the FC at SLAM levels the whole time.
I don’t know anything about a SW pool so I can’t give you any advice going forward. Best thing you can do now is keep FC at slam levels and filter as much as you can.

Good luck. Please forgive me if anything here is wrong. I’m sure someone will correct me.