New Plaster: How fast can I add CYA?

PhillyRay

Well-known member
Sep 29, 2019
51
Philadelphia, PA
Pool Size
35000
Surface
Plaster
Chlorine
Liquid Chlorine
Its been about 5 days since my pool was re-plastered and filled up. So far I have been brushing twice a day and managing pH with muriatic acid.

Question: How fast can I add CYA to my pool?

Based on my instructions, I can and should start adding diluted chlorine and CYA but I don't want to add too fast and risk messing up chemistry or plaster. But I also know that its time to get some sanitizer in there because the CYA and FC levels are nearly 0 due to fresh fill.

For reference, so far I've added 2 gallons of the instant liquid stabilizer (1 yesterday and 1 this morning). I know this stuff is more expensive than other CYA but I'm trying to take the easy wins because I'm exhausted with all the brushing and other up-keep.

Current readings:
FC: 0.5
pH: 8.0 (this was down around 7.6 yesterday but jumped today)
TA: 90
CYA: 0 (not registering on my test yet)
 
Ray, 2 gallons of conditioner is expected to provide about 21 ppm of CYA. That would explain why it's reading low. I would add another 10 ppm at minimum for now. Your might even take the CYA up to 40 later if you get a hot summer sun on the water.

Your FC definitely needs to come up quick. Day 3 is usually when new plaster starts to receive chemicals, so you're risking algae if your contactor didn't add an algaecide. Balance the FC to an expected CYA of 30 per the FC/CYA Levels. As you may already know, the pH will continue to shoot-upwards as new plaster cures for several weeks. Just stay on that one as best as you can.
 
Ray, 2 gallons of conditioner is expected to provide about 21 ppm of CYA. That would explain why it's reading low. I would add another 10 ppm at minimum for now. Your might even take the CYA up to 40 later if you get a hot summer sun on the water.

Your FC definitely needs to come up quick. Day 3 is usually when new plaster starts to receive chemicals, so you're risking algae if your contactor didn't add an algaecide. Balance the FC to an expected CYA of 30 per the FC/CYA Levels. As you may already know, the pH will continue to shoot-upwards as new plaster cures for several weeks. Just stay on that one as best as you can.

Thanks Texas-

As far as I know, no algaecide was added to the pool. The only other additive that's been introduced is sequestrant for metal staining prevention.

I'll plan to add another gallon of stabilizer today and pick up some more until I can get something to register on my test.

This part feels tricky because I don't want to add too much chlorine without sufficient CYA because I feel like the sun will just destroy it quickly. If it makes sense, perhaps I could add some more chlorine tonight? There will be less sun and the filter has been running 24/7 anyway so it should distribute and sanitize.
 
If it makes sense, perhaps I could add some more chlorine tonight?
You can add chlorine at any time of day or night. Whatever works best for your schedule. The key is at no point do we want the FC to fall below the minimum recommended level (based on our current CYA) as noted on the FC/CYA Levels. That's when trouble sets-in (algae). Today I would get the FC up to at least 5-6, continue with brushing, then maintain a good healthy FC level. If you're lucky, you might get ahead of this thing and avert an algae situation. If you get algae, you cannot perform a SLAM Process for at least 30 days with new plaster.
 
Just following up on this, I think things are going well.

CYA: 30
FC: 2

I'm using pool math and yesterday I added bleach to get FC up to 4 PPM so I saw about a 2 PPM loss over a day which seems pretty normal, right?

I may choose to raise CYA a bit more but I'm within range now.

I'm finding that pH is requiring adjustment every other day instead of daily, so I think that's a good sign things are settling down.

and FWIW, I don't know why it took me so long to get a TF 100 kit. Complete game changer along with using liquid bleach.
 
Yes, pH will rise as the new pool plaster cures. A loss of 2 ppm of FC over 24 hrs is good, but you are allowing it to get too low. Increase the FC higher to about 5-6. Never let it fall below 3 ppm. Stay away from the algae monster by referring to the FC/CYA Levels. The TF-100 is a fantastic tool. :goodjob:
 
  • Like
Reactions: PhillyRay
Yes, pH will rise as the new pool plaster cures. A loss of 2 ppm of FC over 24 hrs is good, but you are allowing it to get too low. Increase the FC higher to about 5-6. Never let it fall below 3 ppm. Stay away from the algae monster by referring to the FC/CYA Levels. The TF-100 is a fantastic tool. :goodjob:
Thank you!
 
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.