New pool questions

[CraigW]

So we had a pool built last year, and due to weather they didn't get it finished and filled until the end of the season and then immediately closed it, so this is my first time trying to maintain it. I'm having trouble getting the chemistry under control (mainly pH). So first off, the CYA is 0, when I asked the pool guy (who maintains alot of pools, so I thought I trusted him) he said "please don't add CYA, just let the salt system do it's thing for a little bit, too much chlorine will affect the plaster" He went on to say that CYA is great when using chlorine sticks, but with salt "we only use that if we have to". Fast forward 2 weeks. I have the SWG set at 80%, filtering 12hrs a day at 1900rpm (15K gal pool). I still only have .2-.4 ppm FC, pH continues to rise, and I've been adding muriatic acid every day (between a pint and a quart, depending on the acid demand test from my Taylor test kit). So summary:
FC- .2-.5
pH - 8+ (usually 1-2 drops acid demand)
TA - 60
CH - 320
CYA - 0

Is my whole pH and FC problem due to no CYA? Or is it also possibly from the finish being new? I understand that the SWG running alot will cause the pH to continually rise since sodium hydroxide is a byproduct.

Thanks for any thoughts, I don't want to totally blow off the pool guy since there's some things they still need to take care of, but the water is starting to warm, so I might want to swim, and am concerned about the low FC and high pH, since that's a bad combination for safe water.

Craig

 

[splashpad]

So we had a pool built last year, and due to weather they didn't get it finished and filled until the end of the season and then immediately closed it, so this is my first time trying to maintain it. I'm having trouble getting the chemistry under control (mainly pH). So first off, the CYA is 0, when I asked the pool guy (who maintains alot of pools, so I thought I trusted him) he said "please don't add CYA, just let the salt system do it's thing for a little bit, too much chlorine will affect the plaster" He went on to say that CYA is great when using chlorine sticks, but with salt "we only use that if we have to". Fast forward 2 weeks. I have the SWG set at 80%, filtering 12hrs a day at 1900rpm (15K gal pool). I still only have .2-.4 ppm FC, pH continues to rise, and I've been adding muriatic acid every day (between a pint and a quart, depending on the acid demand test from my Taylor test kit). So summary:
FC- .2-.5
pH - 8+ (usually 1-2 drops acid demand)
TA - 60
CH - 320
CYA - 0

Is my whole pH and FC problem due to no CYA? Or is it also possibly from the finish being new? I understand that the SWG running alot will cause the pH to continually rise since sodium hydroxide is a byproduct.

Thanks for any thoughts, I don't want to totally blow off the pool guy since there's some things they still need to take care of, but the water is starting to warm, so I might want to swim, and am concerned about the low FC and high pH, since that's a bad combination for safe water.

Craig

Did he mention "when they have to"?
Some troubleshooting questions:
Size of the salt cell?
Is the water clear?
How much sun is directly on the pool/for how many hours?

Yes you definitely want CYA in there to protect the chlorine being made by the cell Water Balance for SWGs - Trouble Free Pool

 

[CraigW]

Cell size in my signature, it's a Pentair ICW20, .7lb/24hrs. Water is clear, pool gets probably 8-10 hours of Sun a day. All testing is with a Taylor K-2006.

 

[splashpad]

Cell size in my signature, it's a Pentair ICW20, .7lb/24hrs. Water is clear, pool gets probably 8-10 hours of Sun a day. All testing is with a Taylor K-2006.

So the cell is sized right to the pool size.

I would definitely suggest adding at least CYA/30 and monitoring from there. Really curious why PB doesn't like the CYA in salt pool. :/

 

[Texas Splash]

Craig, I see a couple issues right now to monitor - low FC/CYA (need to watch for algae), and what appears to be an elevated pH. However depending on your water temp there in MD, the chilly water temp may be helping you.

For the CYA. we recommend a min 70 for SWG pools. Curious though - what's your water temp? If the SWG is working well with current temps, then a CYA of 70 is preferred. Always go back to the FC/CYA Levels. You can augment with regular blach if you need a quick "boost" of FC. Keep an eye on the condition of the water for cloudiness or ANY signs of green (algae). If in doubt, do an Overnight Chlorine Loss Test.

For the pH, because the water is probably still a little chilly, a pH of 7.8 is fine, maybe even 8.0. Your plaster may be still curing since it was completed so late, and new paster can increase pH for a few months. Use our PoolMath tool to review your levels and adjust your pH as needed. If your water temp is somewhere around 50-60, I'd stay with a pH of about 8.0 for now (assuming your TA and CH remain the same). Once your water temp increases to 70 or higher, you may want the pH closer to 7.8.

Hope that helps. Lets us know if you have more questions.

Final note: If your pool guy or builder is still managing chemistry for you, best to adhere to what they say for yoru warranty. But fi the pool is all y ours and they are just offering "advice", you can see all our recommended levels in teh link below.

 

[CraigW]

Lol, I thought they were managing it for me since there's some issues with the finish, but they haven't been here in 2 1/2 weeks since they opened it, so being the concerned engineer that I am, I started doing it myself.

Water temp is 68-70 if you believe our floating thermometer.

Thanks for the replies!

 

[CraigW]

Figured I would update. So I pushed on the pool guy about my low chlorine levels (still showing .2 FC, SWG at 80%, filtering 12hrs a day, 0 CYA since he doesn't want me to add any) and he replied "What is the stable chlorine reading. The stable is the chlorine that "stays in the water" if you would like to boost the free chlorine 2 lbs of shock will do that ". Huh? What is "stable chlorine level"? Is he calling combined chlorine stable chlorine? He seems to think 0.2 is a safe FC level? Am I missing something here? I'm beginning to wonder about him, since everything he tells me about FC and CYA is 180deg opposed to every other reference including the SWG manufacturer.

 

[mknauss]

It's your pool.
The 'pool guy' is a dump and runner. He dumps enough stuff each week to make it to the next week. Until it doesn't. And most likely has no clue about the SWCG.

Your pool, but saving his cost each week would seem to be a good idea.

 

[CraigW]

lol...dump and runner....sounds like I need to dump him and run

No cost to me yet, this is still under startup on my original build contract since the pool was finished past the end of last season so salt wasn't added until this spring.

 

[setsailsoon]

Craig,

Your SWG is on the small side. We recommend a SWG that is sized for a pool 2x yours. Once you get your pool lined out with Marty''s advice you'll need to run the SWG at 100% for 8.5 hr to add 2 ppm per day. If you can't get him to change it for a larger capacity at a good price you can just run it this way. The cell may not last as long and when it goes out you can just replace it with and IC40 or other brand with similar capacity. Good news for you is that you have a VS pump so you can increase run time a lot at very low cost. Just need the minimum rpm to make the flow switch work.

I hope this helps.

Chris