need help - CYA dropped after heavy rain

Jump to latest Follow Reply
K

karose7

Member
Mar 9, 2023
15
Leander, Texas
Pool Size
8000
Surface
Fiberglass
Chlorine
Liquid Chlorine
I'm on day 18 of my SLAM and we got 2 days of heavy rain - I drained off 3"s. Tomorrow we have another big rain coming.
I've been losing chlorine too fast, so I tested CYA and it's no longer at 40 like I thought (it was actually about 35, but I rounded up). I can still see the dot when it's to the top (see pics). Am I reading this correctly
40 mark.jpg30 mark.jpgfull.jpgIMG_0237.jpg?

My pool has been clear for almost a week, but still hasn't passed the OCLT. I have done everything mentioned in this forum (scrub, scrub, vacuum, look for hidden spots, and then scrub again- daily!)

How do I add CYA during a SLAM without adding too much (I was way over 200 due to those stupid pucks and had to drain - I don't want a repeat) I'd like to be able to use a couple of pucks when we leave for a week in June.
Any assistance would be appreciated.
 
karose7 said:
I'm on day 18 of my SLAM and we got 2 days of heavy rain - I drained off 3"s. Tomorrow we have another big rain coming.
I've been losing chlorine too fast, so I tested CYA and it's no longer at 40 like I thought (it was actually about 35, but I rounded up). I can still see the dot when it's to the top (see pics). Am I reading this correctly
View attachment 493267View attachment 493268View attachment 493269View attachment 493270?

My pool has been clear for almost a week, but still hasn't passed the OCLT. I have done everything mentioned in this forum (scrub, scrub, vacuum, look for hidden spots, and then scrub again- daily!)

How do I add CYA during a SLAM without adding too much (I was way over 200 due to those stupid pucks and had to drain - I don't want a repeat) I'd like to be able to use a couple of pucks when we leave for a week in June.
Any assistance would be appreciated.
Click to expand...
First, you should, as you are, measure CYA in bright sunlight...but the sun should be at your back, and you should have vial at your waist. And it should be a quick glance to see if the dot is obscured.

Given my experience, you are likely at CYA of 30. If you were to put that third picture at your waist, sun at your back, likely correct with CYA 30.

I would continue slam and use 12 as your FC target for SLAM.

Try again with test tomorrow, sun at your back, waist level, glance.

Have you scrubbed your skimmer? Did you check the weir door for algae in the foam?
 
Thanks for the reply.
It was at waist level, but you're correct I did have it in the sun. I'll retest in the morning.

Yes, I have scrubbed the skimmer, the jets, and around the tiny light.

The reason I tested CYA is because my pool is in direct sunlight all day - 12 hours. I couldn't keep the SLAM level up today, unless I checked it every 30 mins or so.
 
karose7 said:
The reason I tested CYA is because my pool is in direct sunlight all day - 12 hours. I couldn't keep the SLAM level up today, unless I checked it every 30 mins or so.
Click to expand...
That is normal. Test and replace FC every 2 hours or so if possible. It will drop due to UV (sun) and algae consumption. You should not expect to maintain SLAM level. It will come down every test cycle. Slam is about maintaining a high level of FC, not keeping it AT SLAM target every test. It will consume FC as you are killing algae. You are making progress.

OCLT will tell the tale of completing the algae kill.
 
I must've misunderstood some of the postings. I thought the goal was to keep it at SLAM as much as possible.

I've been at this for 18 days and I just can't figure out where there could be any algae. The pool is crystal clear and the filters are clean. I don't see anything coming off the walls/floor when I scrub (and I mean scrub - I've bent my pole scrubbing so hard!)

There was a massive amount of calcium build up on the walls, but most of that has disappeared. There's still a hard water line that won't scrape off. Will that affect the chlorine consumption?
This pic was this evening - the pole is sitting at the 6' end.
IMG_0241.jpg
 
You are at the worst part! The very tail end. Mine was clear for days and took me 3 OCLT's to pass lol then after I let fc drift to normal levels I did another oclt just to be 100% sure
 
I've been reading a lot about "patience", which I understand.
I have a question about the OCLT. The instructions say to test before the sun hits the pool - is that correct, or do I test before the sun comes up? My pool gets sunlight pretty early.
 
karose7 said:
I've been reading a lot about "patience", which I understand.
I have a question about the OCLT. The instructions say to test before the sun hits the pool - is that correct, or do I test before the sun comes up? My pool gets sunlight pretty early.
Click to expand...
First test is 30 minutes after last addition, pump running and after sundown. Morning test is 30 minutes after pump running and before sunrise. You need to get up early to run pump 30 minutes and test before sunrise!
 

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply