Help remediating out of balance water chemistry

gadgetman9

Member
Jul 17, 2014
15
Somers, ct
I have a very close friend who has been having a lot of trouble for a while with his pool (especially algae), so I had him bring me a water sample. These are the results by using a Taylor K2006 test kit and a copper test kit. The pool is an inground 16x32 vinyl liner with a Hayward EC65A filter.

PH - Unreadable. Sample was bright yellow, well below 7.0. Took 57 drops of R-0006 base demand to bring up to 7.4 Surprised algae could survive at that low PH.
Chorine - 4.0ppm
CYA - 90ppm
Alkalinity - Unreadable. Sample turned red immediately after adding R0007. No amount of R-0008 indicator would change the sample to green
Calcium - 120ppm
Copper 0.4ppm (from algecide)

Since it is an acid, is it possible that the CYA has driven the PH so low?

He's been dumping a lot of shock in. Could that drive PH down?

According to the Taylor charts (I had to extrapolate for 57 drops of base demand), he would need to add 30 Lbs of sodium carbonate to bring PH up to 7.4. Should he actually add 30 Lbs? If so, I assume gradually over a week?

He uses chlorine tabs and shock powder to treat the pool. He said he took a sample to a pool store and they sold him the chemicals he needed. Imagine his surprise when I told him their main purpose is to sell pool chemicals.o_O

Any advice here would be appreciated. I'm guessing he's going to have to dump some water.
 

Jeff J.

Well-known member
Aug 6, 2019
179
Staten Island NY
I have a very close friend who has been having a lot of trouble for a while with his pool (especially algae), so I had him bring me a water sample. These are the results by using a Taylor K2006 test kit and a copper test kit. The pool is an inground 16x32 vinyl liner with a Hayward EC65A filter.

PH - Unreadable. Sample was bright yellow, well below 7.0. Took 57 drops of R-0006 base demand to bring up to 7.4 Surprised algae could survive at that low PH.
Chorine - 4.0ppm
CYA - 90ppm
Alkalinity - Unreadable. Sample turned red immediately after adding R0007. No amount of R-0008 indicator would change the sample to green
Calcium - 120ppm
Copper 0.4ppm (from algecide)

Since it is an acid, is it possible that the CYA has driven the PH so low?

He's been dumping a lot of shock in. Could that drive PH down?

According to the Taylor charts (I had to extrapolate for 57 drops of base demand), he would need to add 30 Lbs of sodium carbonate to bring PH up to 7.4. Should he actually add 30 Lbs? If so, I assume gradually over a week?

He uses chlorine tabs and shock powder to treat the pool. He said he took a sample to a pool store and they sold him the chemicals he needed. Imagine his surprise when I told him their main purpose is to sell pool chemicals.o_O

Any advice here would be appreciated. I'm guessing he's going to have to dump some water.
Trichlor tabs are acidic and will lower PH and TA. I used them for years and both zeroed out for me. Dichlor powder is also acidic. Both will add CYA quickly. Cal-hypo powder adds calcium. According to the chlorine cya chart, Chlorine / CYA Chart - Trouble Free Pool, at 90 CYA his chlorine should be between 10-12, and not drop below 7.

In my opinion, he should add liquid chlorine to get up to 12. Use PoolMath, PoolMath. No more tabs or powder. Bring the PH up to at least 7.2. You can add baking soda to raise PH and TA. He can either do a partial drain and refill, or work with the 90 CYA and let it come down over time.

I'm no expert, just what I learned from TFP.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
34,056
Sebring, Florida
First, I would drain half of the pool to get your CYA down to around 50 and your copper down below .2 ppm.....PLEASE don't use any more copper anything!

Then, refill your pool.

Then, you have to get pH and TA in a range you can test. Start by bringing the TA up until you can read it. 70 ppm would be perfect. Once your TA is around that level, then test your pH and adjust it to about 7.4 either with 20 mule team borax to bring it up or muriatic acid to bring it down. I am almost sure it will be too low so plan on the 20 mule team borax.

Once you can get those two tests in a range you can read, post up the complete results like this

pH
FC
CC
TA
CYA

Final thoughts about helping a friend......No good deed goes unpunished!

Unless you get them to log on here and learn how and why their pool got the way it did, they will go right back to the same type of pool water management.
 
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mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
31,077
Laughlin, NV
Jeff has a good start.
The vinyl liner is at risk with that pH. It will get brittle and fail pretty rapidly.

Use Poolmath. Assume TA 0 and pH 6.8. Use Soda Ash (washing soda). It will raise both TA and pH. You many overshoot on TA but you need pH up now. Then a large water exchange.

You do not show a volume. Use pH of 6.8 and TA of 0 in Poolmath. Add the soda ash, circulate for 30 minutes, run the tests again.

I have never used the base demand. If you are confident of that, then go ahead, but do in thirds. Add one third of what you come up with, circulate, and test. Repeat.

EDIT -- I see Dave chimed in. A drain first is great if done today!
 

gadgetman9

Member
Jul 17, 2014
15
Somers, ct
Assume TA 0 and pH 6.8
Since the TA sample showed red immediately after adding 2 drops of R-0007 and before adding the indicator R-0008 which is supposed to turn it green, shouldn't I assume the TA is high? It's not supposed to turn red until the R-0008 indicator is added.

Also, the volume is 16,500.
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,873
San Dimas, CA (LA County)
Since the TA sample showed red immediately after adding 2 drops of R-0007 and before adding the indicator R-0008 which is supposed to turn it green, shouldn't I assume the TA is high? It's not supposed to turn red until the R-0008 indicator is added.

Also, the volume is 16,500.
If the pH is below the bottom of the scale, you can't have much alkalinity. And whatever the reading actually is doesn't atter because its going to change when water gets replaced.

I sure hope the pool in question doesn't have a heater, because that could be where the copper came from. Check out the pictures. Maintain your chemicals correctly
 

gadgetman9

Member
Jul 17, 2014
15
Somers, ct
I sure hope the pool in question doesn't have a heater, because that could be where the copper came from. Check out the pictures.
The copper came from an algaecide he used and he kept a copper pipe in the pump basket. He does not have a pool heater.
He has a new problem now. He got the Ph up to 6.8 from 0. Now he says the liner is brown from metal deposits. He has had this problem in the past when he raises the ph and spends hundreds of $ on chelation chemicals to get rid of it.

I have a copper/silver ionization system in use for the past 12 years with no such issues. I keep the copper at 0.3ppm. No staining, no algae and no problems. Ph is 7.6, CYA is 43, TA is 105 and chlorine is 2.0. Water is crystal clear and everyone says how nice the water is. My wife says the water feels softer since I raised the calcium levels to 300.

I can't get him to SLAM the pool with 35ppm chlorine (CYA is at 90). He is maintaining it at 10-12. Is he really getting metal staining by raising the Ph?