Should we do a partial drain and fill?

SwimdailyAZ

Member
Oct 5, 2019
16
Phoenix, AZ
Our test kit should arrive today. We are planning to take over our pool once we get the kit.

The pool company added 6 gallons of liquid chlorine to our pool last Friday. Today they added Thiotrine to neutralize some of the chlorine and did not add any chlorine tabs to the floater.
I'm making the assumption that 6 gallons of liquid chlorine was too much or the CYA levels are too high since the chlorine is still testing high a week later and no tabs were added to the floater.

I'm just wondering if we should do a partial drain and fill to reduce chlorine levels, CYA, and CH, thereby improving water quality & increasing the effectiveness of FC chlorine while using less chlorine or use chemicals to fix it?

Does filtering the water reduce CYA and Chlorine levels or just CH levels?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
10,487
Northern NJ
Post a complete set of test results:

FC
CC
Ph
TA
CH
CYA
Water temp

Your signature does not show what type of pool you have - plaster? vinyl? fiberglass? spa?

Filtering does not reduce any chemical levels. CYA and CH only drop from draining. CL consumption is 2-4 ppm a day for an outdoor pool.
 

SwimdailyAZ

Member
Oct 5, 2019
16
Phoenix, AZ
I want to make sure I did the CYA test correctly.
I filled the mixing bottle to the bottom of the label with pool water then
added the R-0013 to the top of the label and mixed.
With the sun at my back, I poured the mixture into the cylinder
the black dot disappeared before it hit the line marked 100.
So I repeated the test filling the mixing bottle to the bottom of the label with pool water
adding tap water to the top of the label, mixing then pouring off the water to the bottom of the label and adding R-0013.
I got the exact same results as the first test.
If this is correct then my CYA level is above 200. My estimate is more like 240 as it's about 2 lines short of the line marked 100.

I still have to do the rest of the tests but I wanted to make sure I got this one right.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
10,487
Northern NJ
If this is correct then my CYA level is above 200. My estimate is more like 240 as it's about 2 lines short of the line marked 100.

I still have to do the rest of the tests but I wanted to make sure I got this one right.
Correct. Your CYA is 200+.

You need to do a drain or water exchange of about 80% of your water to get your CYA down to 30-50.

See No Drain Water Exchange

How do you intend to chlorinate your water? Liquid Chlorine? Salt Water Generator?
 

SwimdailyAZ

Member
Oct 5, 2019
16
Phoenix, AZ
We use tablets right now. Since we need a drain and fill are liquid chlorine, dry acid, baking soda, borax, and CYA the only chemicals I need to have on hand?
Given our harsh summer sun here in AZ should I only use tablets to maintain chlorine levels during the day and use the liquid in the winter? Our pool gets mostly direct sunlight during the day and water temps get to about 92 degrees in the shallow end when its 110 degrees and 94 at 115 degrees.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
10,487
Northern NJ
We don’t recommend using dry acid on plaster pools. It adds sulfates to the water that can damage the plaster. Use muriatic acid.

All you should need regularly is liquid chlorine, muriatic acid, and stabilizer.

Keep your CYA around 50 and follow the FC/CYA Chart

Consider getting a SWG.
 
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SwimdailyAZ

Member
Oct 5, 2019
16
Phoenix, AZ
Here's a blog post by a company that says recycling pool water through an R/O filter will lower CYA.

Is this not an option because our CYA is 200+ or is it not possible to remove CYA using reverse osmosis and it's really dilution causing the CYA to lower?

The Puripool Process To Lower Cyanuric Acid | Pure Water Industries

Our pool doesn't have a central drain and we don't have a clean-out anywhere that I've seen to dispose of the water. When we backwash the water evaporated off the brick within an hour so it's no big deal but, that will not work here. Would we have to get a truck to dispose of the water?
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
11,522
Evans, Georgia
Just as a point of reference, rarely does anyone *need* to lower their FC. The sun does a pretty good job of it, even with CYA in the water. It should lower over days, and as long as its less than you SLAM process level of FC its safe to swim in. This does assume you know your CYA level and your FC level, of course. :)

Maddie :flower:
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
32,843
Sebring, Florida
Reverse Osmosis will work fine for your pool but be prepared to pay a TON more than just to replace water. You don't say how big your pool is but I recently saw a quote of $660 for a 20k pool.

Whatever you decide is fine but it is imperative you reduce your CYA and use no more pucks (that's what is causing your high CYA) A CYA of 200+ makes your pool almost unmanageable.

Please read "The "ABC's of Pool Water Chemistry" up in Pool School
 

SwimdailyAZ

Member
Oct 5, 2019
16
Phoenix, AZ
It's 15,000 gallons nothing fancy no waterfall feature or spa spillover or anything.

Before ripping into the pool company I thought I should test the FC and had to use the over 5ppm test. To recap the pool company added 6 gallons of liquid chlorine on Friday the 4th. Then on Friday the 11th they added 2 cap fulls of Thiotrine to lower the chlorine levels. It's now Sunday I added 200 drops one drop at a time while swirling which only got me to white cloudy water in the cylinder. Because I didn't want to use up any more of the drops I stopped 200 drops x .5 = 100ppm.

If slamming yellow/mustard algae is 60% of the CYA (200 x 60%= 120ppm) the pool guy had to get the FC up to 120ppm. Meaning he had to test the CYA level before coming to that number. We assumed the pool guy didn't do a CYA test but, it seems he did.

I know who gets to pay for draining and refilling the pool along with the disposal of the water.
 

Frodo

Member
Jul 5, 2014
19
Central New Jersey
Before ripping into the pool company I thought I should test the FC and had to use the over 5ppm test. To recap the pool company added 6 gallons of liquid chlorine on Friday the 4th. Then on Friday the 11th they added 2 cap fulls of Thiotrine to lower the chlorine levels. It's now Sunday I added 200 drops one drop at a time while swirling which only got me to white cloudy water in the cylinder. Because I didn't want to use up any more of the drops I stopped 200 drops x .5 = 100ppm.
You used 200 drops performing the DPD chlorine test? When you added the DPD powder to your water sample, did it turn purple at all?
 

SwimdailyAZ

Member
Oct 5, 2019
16
Phoenix, AZ
Sorry for the delay. It turned a bright purple/pink color instantly. At 200 drops I stopped adding the drops (added 1 at a time while swirling).
The pool company has been using chemicals since the 11th of October to reduce the chlorine levels. Our pool gets full sun until around 2 when one side of the deep end gets some shade. I assume it's the CYA causing the chlorine to not burn off.
Tests were done using the TF-100 test kit.
 

SwimdailyAZ

Member
Oct 5, 2019
16
Phoenix, AZ
A word to the wise. We bought a 1/3 HP Superior Utility Pump with a 1 1/4" discharge pipe and comes with an adapter to use a water hose. Be aware that it doesn't come with a 1 1/4" discharge hose or an adapter to connect the discharge hose to the pump.

The 1 1/4" hose kit comes with 2 adapters and a hose clamp but neither adapter can be used to attach the hoses to each other or used to attach the hose to the pump.

The adapter to connect the hose to the pump has threads on the inside and outside which don't make sense because the hose isn't threaded. They don't offer an adapter to connect two hoses together. Superior told me you have to make your own adapter to attach the hoses together.

The adapter needed to attach the hose to the pump is cheap enough at only $5.50 however, Superior charges as much to ship it as the cost of the part. I ordered 2 to be safe since they are plastic and shipping was $10.80 (not disclosed until you get an e-mail confirming the order). I love family-owned companies but, not a fan of this one. Glad we ordered the pump via Home Depot.

Amazon has the hose kits but not the adapter.
My $60.00 pump became $114.00 pump.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
10,487
Northern NJ
I am trying to understand where your problem is. The Superior pump is fine when used with a garden hose. You wanted to use it with a larger 1 1/4" hose you got from Superior.

You lose me when you said "neither adapter can be used to attach the hoses to each other'? What two hoses are you talking about?

You get this hose?


Are you saying the adapters that come with that hose do not fit the pump outlet and you needed to order a different one from Superior?
 
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Pv2

LifeTime Supporter
Aug 14, 2013
472
south east Arizona
It's 15,000 gallons nothing fancy no waterfall feature or spa spillover or anything.

Before ripping into the pool company I thought I should test the FC and had to use the over 5ppm test. To recap the pool company added 6 gallons of liquid chlorine on Friday the 4th. Then on Friday the 11th they added 2 cap fulls of Thiotrine to lower the chlorine levels. It's now Sunday I added 200 drops one drop at a time while swirling which only got me to white cloudy water in the cylinder. Because I didn't want to use up any more of the drops I stopped 200 drops x .5 = 100ppm.
did you use the right reagent? my (admittedly not well skilled) guestimate using pool math says 6 gallons of 10% LC for your 15000 gal pool should have only raised the chlorine to 67 ppm? (even the 12.5% LC would only raise it to 83 ppm)
 

SwimdailyAZ

Member
Oct 5, 2019
16
Phoenix, AZ
A word to the wise. We bought a 1/3 HP Superior Utility Pump with a 1 1/4" discharge pipe and comes with an adapter to use a water hose. Be aware that it doesn't come with a 1 1/4" discharge hose or an adapter to connect the discharge hose to the pump.

The 1 1/4" hose kit comes with 2 adapters and a hose clamp but neither adapter can be used to attach the hoses to each other or used to attach the hose to the pump.

The adapter to connect the hose to the pump has threads on the inside and outside which don't make sense because the hose isn't threaded. They don't offer an adapter to connect two hoses together. Superior told me you have to make your own adapter to attach the hoses together.

The adapter needed to attach the hose to the pump is cheap enough at only $5.50 however, Superior charges as much to ship it as the cost of the part. I ordered 2 to be safe since they are plastic and shipping was $10.80 (not disclosed until you get an e-mail confirming the order). I love family-owned companies but, not a fan of this one. Glad we ordered the pump via Home Depot.

My $60.00 pump became $114.00 pump.
 

SwimdailyAZ

Member
Oct 5, 2019
16
Phoenix, AZ
The pool guy added the 6 gallons of liquid chlorine plus added 4 tabs to the floater on 10/4/19 but nothing since then. I tested the FC on 10/13 and it was 100+. I just tested it today 10/30 and the FC level is 30+ again I stopped adding drops at 60 as the water still wasn't clear.
When we talked to the pool company about two weeks after they added the 6 gallons and was told they were still trying to lower the chlorine levels.
I asked him, if they checked the CYA levels before adding all the chlorine and they said, no. It's not something we usually test. So, how they determined the target FC level to achieve and how much liquid chlorine was needed to achieve the target is unknown. Or if, they took into account the amount of FC that already existed in the water.

PV2, my math says if you have 20ppm and add enough chlorine to raise it by 83ppm you get 103ppm not 83ppm.

I also assume you have to take the time of year into account if you want to slam the water? Do it in the summer here in AZ and the FC will drop quickly due to the intense UV whereas in winter the FC drops slowly because the sun is further away. For those who live near the equator, this wouldn't hold true as the UV intensity never changes.

Today our PH tested at 7.2ppm. Does Thiotrine affect the PH?

I'm sorry if it sounds like I'm just complaining, it's not my intent. Since I don't know the history of our water quality and the pool company cannot tell me. It's very hard to communicate without it coming off as accusatory. I also want to learn from this experience and for the pool company to realize what he did wrong so he doesn't do this to someone else.