Drain and refill question water chemistry question.

[Cyclist7531]

So, I've decided to do a drain or maybe partial drain and refill and have a couple of questions about water chemistry after the refill. I've been having high
CH for close to 3 years now and would like to bring it down plus with all the rain we've had my pool has taken on a dull haziness.
I've cleaned my filters and checked the manifold on the Jandy CL460 for any cracks and found none. Pump has been running 10hrs/day.
Did a OCLT and it dropped .5 With these readings my pool is still hazy. Pool is quartz plaster of about 9500 gal.
This is a salt pool but currently treating with liquid chorine.

My tap water has the following readings using TF-100 tests
PH 7.8
TA 80
CH 100

My current pool readings are:
FC 6.5
PH 7.6
TA 90
CH 650
CYA 40

According to pool math to bring my CH down to around 325 I need to replace about 60% or so.
I will be swapping in new filters but would like advice on how to manage the chemistry once it's filled.
I know the CYA will be low but how should I manage the FC level along with bringing up the CYA?
I will check the other readings as well to see what they are but any advice would be helpful.

Will worry about salt later when I close to turning on the SWG in March.

Thanks

 

[duraleigh]

haziness - what is your current psi? I would suggest 24/7 runtime on the pump and elevate the chlorine to 8-10 ppm for maybe 48 hours. I think that will clean up your pool.

High CH 2 -50% drain and refills should get you in a good range. Any reason you can think of why CH is high?

 

[Newdude]

+1. Unless you have visible scaling, many have managed similar CH levels as yours.

In the last couple weeks, you've either dipped below minimum (4 fc for your 50 CYA. FC/CYA Levels) or you've danced the line.

Overnight Chlorine Loss Test to see if the cloudiness is something brewing.

 

[Cyclist7531]

haziness - what is your current psi? I would suggest 24/7 runtime on the pump and elevate the chlorine to 8-10 ppm for maybe 48 hours. I think that will clean up your pool.

High CH 2 -50% drain and refills should get you in a good range. Any reason you can think of why CH is high?

Pool has had high CH since day after pool builder did an acid bath to address issues with the plaster. Been high ever since. After I put new filters I can try and bump up the FC and will run 24/7 for a couple of days.

 

[Cyclist7531]

+1. Unless you have visible scaling, many have managed similar CH levels as yours.

In the last couple weeks, you've either dipped below minimum (4 fc for your 50 CYA. FC/CYA Levels) or you've danced the line.

Overnight Chlorine Loss Test to see if the cloudiness is something brewing.

Looking at my logs on pool math I did dip below 4 to 3 (which at the CYA of 40 I would be at the min) a couple of times so perhaps. I have managed the CSI pretty well but still get some scaling and flakes off the SWG during the summer.
Did an OCLT and it dropped by .5

 

[Newdude]

OK so you passed an OCLT to rule out an algae bloom being kept at bay for the time being, and you have visible flakes/scaling and would likely benefit from a drain. The details are HUGE here, but we were just looking out for you.

Draining/exchanging is an ordeal, and your 100 CH fill water will lower some of your efficiency as you'll be adding some back. I suggest overshooting the target because in a high evaporation environment, you'll be rising again immediately and will be high that much sooner if you only drain to in range. Multiple drains reduce the efficiency also, and being such an ordeal, I'd want to buy as much time as possible until the inevitable next one. See the link below and hatch a plan for which method will work best for you.

Draining - Further Reading

www.troublefreepool.com

 

[Cyclist7531]

Great. Thanks for the reply. Much appreciated.
I’ll give the link a read and go from there with fingers crossed

 

[Newdude]

I’ll give the link a read and go from there with fingers crossed

Keep us posted and we'll help.

 

[Cyclist7531]

Keep us posted and we'll help.

Will it help at all to use a hose end filter when I refill?

 

[Newdude]

Will it help at all to use a hose end filter when I refill?

Those are mostly gimmicks.

 

[Cyclist7531]

Those are mostly gimmicks.

Thanks

 

[Cyclist7531]

Newdude, could use your advice after the drain and refill. So, after replacing about 78% of the water my readings are as follows:

FC 1.5
PH 7.8
TA 80
CH 225 - down from 650 so overshot the target a bit.
CSI is -.43

I haven't checked CYA yet but I imagine it's pretty low.

So, wondering what you would suggest I do next regarding bringing up FC and CYA and to what levels? And what about CH since
it's below recommended level of 250 and ideal of 325.
We are looking at partly cloudy to cloudy skies for the next few days with a chance of some light rain on Fri and Sun

Thanks, Mark

 

[Newdude]

CH 225 - down from 650 so overshot the target a bit

AWESOME !!!! It'll likely rise soon enough. Hang tight and monitor it at times.

So, wondering what you would suggest I do next regarding bringing up FC and CYA and to what levels?

Bring FC to 5 for now and keep it there.

Get a good CYA reading and bring it to 30 if needed.

Overnight Chlorine Loss Test to ensure there's no need to SLAM before going to 70 CYA for the SWG. It's early in the season still and you can get by with a lower CYA for now. Also, when bumping up the rest of the way to the 70, undershoot and creep up to it. It's real easy to go over and you'll be draining again if you overshoot.

 

[Cyclist7531]

AWESOME !!!! It'll likely rise soon enough. Hang tight and monitor it at times.

Bring FC to 5 for now and keep it there.

Get a good CYA reading and bring it to 30 if needed.

Overnight Chlorine Loss Test to ensure there's no need to SLAM before going to 70 CYA for the SWG. It's early in the season still and you can get by with a lower CYA for now. Also, when bumping up the rest of the way to the 70, undershoot and creep up to it. It's real easy to go over and you'll be draining again if you overshoot.

Great. Thanks again

 

[Cyclist7531]

AWESOME !!!! It'll likely rise soon enough. Hang tight and monitor it at times.

Bring FC to 5 for now and keep it there.

Get a good CYA reading and bring it to 30 if needed.

Overnight Chlorine Loss Test to ensure there's no need to SLAM before going to 70 CYA for the SWG. It's early in the season still and you can get by with a lower CYA for now. Also, when bumping up the rest of the way to the 70, undershoot and creep up to it. It's real easy to go over and you'll be draining again if you overshoot.

After bringing up FC and CYA should I run the filter pump 24hrs for a couple days?

 

[Newdude]

After bringing up FC and CYA should I run the filter pump 24hrs for a couple days

Oh yeah. FC needs 15 mins to mix with good circulation but CYA needs a day or two once it's dissolved. Do the carrot on a stick (in a sock) method in front of a return. If you use the skimmer it can get trapped in the filter and take a week or more.

Also make sure it's good and mixed when getting your CYA baseline. Otherwise you add more than you needed and we're right back to square one for new reasons.

 

[Cyclist7531]

After bringing up FC and CYA should I run the filter pump 24hrs for a couple days?

CYA is probably zero since the black dot never disappeared. Salt is 600 which brought my CSI down to -.16. Not too worried about salt now as I typically won't fire up the SWG until late March. Can I add both CYA and Chlorine at the same time? I actually have a jug of liquid CYA. Should I pour it slowing in front of a return or slowly into the skimmer?

 

[mknauss]

Liquid CYA should be poured into the skimmer. VERY slowly. Be sure to shake that bottle as much as you can.

Add it and then add the chlorine in front of a return. No need to wait in between.

 

[Newdude]

CYA is probably zero since the black dot never disappeared

It's good and mixed, right ? Becausr your fill water had 0. If it's good and mixed, add 20 and see if it registers. Then add to 30 if need be, allowing each add to mix.

Marty has you covered above with the how's.

We'll tackle the salt once the pool is up and running well on liquid chlorine. Don't want to do too much and goof. Focus on one at a time.

 

[Cyclist7531]

Liquid CYA should be poured into the skimmer. VERY slowly. Be sure to shake that bottle as much as you can.

Add it and then add the chlorine in front of a return. No need to wait in between.

Thanks. Typically I would do the dry CYA in the sock method but in this case I wanted to get the CYA in without waiting for the dry to be fully dissolved. Based upon my pool size I think one gallon will get me close to a CYA of 30. I do have some dry if I need to bump it up some but won't bring it all the way up to SWG range until I get close to turning on the SWG in March.