Opening a friend's green pool and need help with water...

[AveMaria472]

I am working on a pool for a friend who is out of state and can't take care of it.
Statistics on this pool:
21x43 oval above ground
vinyl liner
21,311 gallons
2hp Aquqa Pro variable speed pump
24", 300# sand filter
inline SWG connected but not in use during opening/SLAM
There is a large heater also, but we won't be worried about that.
I have no "history" of what was put in the pool in the past because my friend just bought the house. Given the array of pool "supplies" left by the previous owner in the garage (3" pucks, algaecide, etc, etc, etc) I'm thinking it wasn't any method taught here on TFP!

I opened the pool to a green mess. I even had to scoop a couple of dead things out of the water. I had to add a lot of water in order to run the pump. Once I could turn on the pump, I added 4 gallons of 12% LC to get the process going. I did see a change in the right direction overnight. That was a couple of days ago.

Latest Test Results with new TF-100 test kit are:
CYA 0 (will add using sock method according to Pool Math)
CH 100
TA 200

Before I start the SLAM, should I adjust the CH or TA? If so, how?
The water sample I used to test was over 24 hours old, so I did not test the PH yet.
Should I test the PH of a green pool or just adjust it after I SLAM it?

Thanks for your help! @mknauss @Texas Splash

 

[mknauss]

Follow the SLAM Process. Read the article. Adjust pH to 7.2. Add 30 ppm worth of CYA.

 

[Newdude]

Because of the green mess that has been so for an unknown time, and 0 CYA while there's proof it was likely closed with sky high CYA from pucks/shocks, you should test for ammonia before adding CYA.

It's real simple and if you're 'wrong' then it only jump starts the SLAM process. Add 10 FC and test 30 mins later. If it's less than 8 FC, continue 30 minute tests/adds until it holds 8 FC. Then add 30 CYA and slam away.

Ammonia - Further Reading

www.troublefreepool.com

 

[mknauss]

In the OP's other thread they stated the friends pool held FC of 4 ppm well after adding chlorine. So ammonia is not likely.

 

[Newdude]

Sorry. I'm late to the party. Carry on.

 

[AveMaria472]

Ok my son and I just drove down to the pool.
I tested the Ph and it’s sky high (a dark purple color). I didn’t have any muriatic acid and not sure how I can figure out how much to put in when the ph was off the chart on the test tube.

We also:
Backwashed the filter
Checked the skimmer
Hung the stabilizer in the socks by the return
Brushed all the walls and floor
Cleaned the robot and restarted it
Added 4 jugs of chlorine (so we don’t go backwards, until I get the muriatic acid)

Here’s a pic… because it’s oval and the skimmer and return are at the end (on the left), the right side of the pool has stayed greener. Any tips on what we can do to help circulate that better? I do have the pump running on high. And when we restart the robot, we put it in on that end.

Thanks for your help!

 

[mknauss]

What was the TA?

 

[AveMaria472]

Latest Test Results with new TF-100 test kit are:
CYA 0 (will add using sock method according to Pool Math)
CH 100
TA 200

Before I start the SLAM, should I adjust the CH or TA? If so, how?
The water sample I used to test was over 24 hours old, so I did not test the PH yet.
Should I test the PH of a green pool or just adjust it after I SLAM it?

@mknauss I listed the TA earlier

 

[mknauss]

OK -- so with that TA, you will not be able to crash the pH.

Using PoolMath, assume pH of 8.2 as current (be sure TA is entered) and Target is 7.6. Add the acid, circulate for 30 minutes, retest, repeat. Test TA every few times and adjust in PoolMath. Once pH reads mid 7's or lower, start SLAM.

 

[AveMaria472]

OK -- so with that TA, you will not be able to crash the pH.

Using PoolMath, assume pH of 8.2 as current (be sure TA is entered) and Target is 7.6. Add the acid, circulate for 30 minutes, retest, repeat. Test TA every few times and adjust in PoolMath. Once pH reads mid 7's or lower, start SLAM.

I’m curious why it is recommended to adjust the PH before starting a SLAM? I’m sure there are reasons, just curious what they are. I know the PH test is inaccurate at high chlorine levels. But does high PH affect the actual SLAM process?

 

[mknauss]

Main reason is you cannot test pH during SLAM. Also, there is some marginal advantage to a lower pH with elevated FC even with CYA.

 

[AveMaria472]

Main reason is you cannot test pH during SLAM. Also, there is some marginal advantage to a lower pH with elevated FC even with CYA.

https://www.troublefreepool.com/posts/4121/bookmark

Was that bookmark supposed to take me to a post? The link didn’t work

 

[mknauss]

Sorry --- I will try again.

Pool Water Chemistry

This thread presents my findings so far on pool water chemistry including the following: More Accurate Calcite Saturation Index (CSI) to replace Langelier Saturation Index (LSI) Calculation of ppm HOCl (disinfecting chlorine) at various levels of Total Free Chlorine (FC) and Cyanuric Acid (CYA)...

www.troublefreepool.com

 

[AveMaria472]

OK -- so with that TA, you will not be able to crash the pH.

Using PoolMath, assume pH of 8.2 as current (be sure TA is entered) and Target is 7.6. Add the acid, circulate for 30 minutes, retest, repeat. Test TA every few times and adjust in PoolMath. Once pH reads mid 7's or lower, start SLAM.

I found a bottle of muriatic acid left in the garage. Not sure the age of it, but the garage is HOT, and I’m not sure how that will affect it. It’s a gallon bottle but only 1/4 full so won’t be enough for what I need anyway. Should I bother using it or just use fresh?

 

[mknauss]

You can use it. Acid does not degrade. Be careful of the bottle as it may be brittle.

 

[AveMaria472]

Unrelated question… I need to replace the cord on my Dolphin Active 10. Marina Pool, Spa, and Patio has a replacement. Is there a coupon code for the website? I know they’re recommended often here so I thought I’d check before ordering.

Maytronics Dolphin 99958902-DIY Cable 12M

Lowest Prices Guaranteed. Same Day Shipping. THE Leading Experts of Maytronics Dolphin Replacement Parts and Robotic Pool Cleaners. Authorized Service Center and Elite Dealer. All Maytronics Parts Available. Call 303-985-0077 if you do not see the part you need or if you need assistance with...

marinapoolspaandpatio.com

 

[AveMaria472]

Making great progress in this pool! The pool looks clear except for this white-ish/light gray stuff at the bottom. Kind of looks like a wet tissue in the water, but when we brush it, it goes up into a cloud in the water. We are cleaning & restarting the robot, as well as brushing the whole pool every time we go to the pool. Still maintaining SLAM level also. Any idea what this stuff could be? When I ran my tests this morning CC’s were zero.

 

[PoolStored]

Dead Algae.