CYA super low, chlorine @ 11

[Captsuperfly]

Hello,

First, thanks for all the help on here. I've been learning a more and more about my pool chemistry, gotten a real test kit etc.

I've got a new IG vinyl liner pool with a SWG. Last week we had a bunch of people in the pool and when I left the house on Sunday (we really only make it out on weekends) I cranked the SWG to 90 percent because the chlorine was low (say 4ppm) Tested when I got back yesterday and it was very high (11PPM). CC is almost nil.

I've turned off the SWG and figured I'd keep a close watch and see what a day or two of bright sun did to it.

This morning I did my first proper CYA test with the Taylor kit (I'd been using the strips which had it on the low side of acceptable) and, while the solution does get cloudy when I mix it, I can't get the little black dot in the test tube to disappear. So, obviously, it's very low and I need to bring it up.

People coming over tomorrow and rest of week to use the pool. I'll be here all week to monitor.

Questions are:
1) do I let the chlorine come down a bit before I add the stabilizer? Or start trying to raise the CYA immediately?
2) Given the CYA levels are so low, should I keep the SWG on low to avoid a sudden drop? (even though the chlorine is high now?)

In other news PH is around 7.6. TA is 125

 

[Pool Tool]

Add your CYA now. If you hang the granular CYA in front of the return and squeeze it will mix in as little as a few hours. Add your signature so we can see pool size, etc.

What was your FC this morning? Test results always best in this form or similar:

FC
CC
pH
TA
CH
CYA

 

[Captsuperfly]

Thanks for the help.
FC: 11 (THis morning)
CC .1
PH 7.6
TA 125
CYA guessing less than 20
Sorry, I'll set up my signature later but the pool is 18X32 (20,000 Gal) vinyl. Hayward Salt Cell

 

[Pool Tool]

No problem. So FC was 11 last night and 11 this morning - very good! CC of .1 is an estimate?? No big deal, but if it turned just kinda pink then most will say to call it <0.5.

I would add 5 lbs of granular CYA - this will raise your CYA by 30 ppm. Hang two socks, one in front of a return and let it soak. If only one return just combine to 5 lbs in one sock. Then retest CYA in a few days. You should end up around 50-60 ppm, which you can then inch your way up to 70 for your SWG. Slow is good with CYA.

Once you hang the CYA, turn your SWG back on and shoot for 4-5 ppm.

 

[Captsuperfly]

thanks again. I will go slow since I'm off this whole week to keep an eye on it.

 

[Captsuperfly]

Update:
Kept SWG off today (moderate sun)
Added 2.5 pounds of stabilizer (going slow to avoid a spike (it's my testing I don't trust, not the advise here)

Here's the EOD day totals
FC 7.5 (took 15 drops on a 10ML sample)
CC .5
PH: 7.8 (up a bit)
TA 125
CYA 30-40 (at least the dot finally disappeared!)

On the CYA front, Might give it a full 48 hours to dissolve before I add any more. I'll test tomorrow night and see if any change.
I've left the pump on 24/7

HUGE rain coming tonight, so I turned the SWG back on at 40 percent. I'd rather wake up to FC than a green pool, right?

I may add some acid to drop the PH tomorrow... or should I get the CYA up first?

thanks again for all help.

 

[Pool Tool]

Nice to see the test results reflect what you expect them to. You're getting the hang of it quickly, nice job!

The acid and CYA can be done at the same time. No problems there at all.

Sent from my SM-G930V using Tapatalk

 

[Captsuperfly]

thanks again for the help with all this.