plz help chemistry 0

[newpoolbuild]

Pool water filled last Th. Shocked on Fri. Added 4 tabs in the skimmer. Can someone plz help me make sense of my water chemistry? What should I do now? Plz see my pool log. I used the TF 100 kit. PH 8.2, Total C 0, FC 0, CC 0, CYA 0, Alkaline 200, Calcium 325. The PB told us to run the pump 12 hr/ day right now.

 

[Msch99]

Add more MA to lower your PH to ~ 7.2 Your TA will slowly come down as you add MA to lower rising PH.
You need to add CYA/Stabilizer to get to 40 ppm or so. See chlorine/cya chart in my signature. Add enough to get to 30, wait a day, then add enough to get to 40.
In the mean time, add liquid chlorine to 5ppm daily while CYA is ~ 30, then 6ppm after add to get to 60 CYA, until your ready to start SWG.

 

[PoolNewb2020]

When adding CYA account for the 4 tablets you added to the skimmer. Once they fully dissolve they will add about 10ppm worth of CYA. So like mentioned above add 30ppm first and them wait until tablets are fully dissolved and measure CYA again.

Add 5ppm worth of liquid chlorine ASAP. It cannot be stressed enough. Chlorine is the only thing keeping algae at bay. Not PH, not TA, not anything else, but FC. Other chemistry can be adjusted with much less urgency.

 

[Johnny_5]

I don't think the chlorine will have much sanitizing effect with a PH of 8.2. Wouldn't you want to get that down first?

 

[mknauss]

I don't think the chlorine will have much sanitizing effect with a PH of 8.2. Wouldn't you want to get that down first?

Prior to SLAM it is good to lower pH to 7.2. But there is little effect on the chlorine effectiveness with CYA in the water.
Getting the pH to 7.2 is because when at SLAM level FC, you cannot test pH.

 

[newpoolbuild]

Thank you all for the prompt reply. Dumped 1 gallon of liq bleach in the pool last night and the pump kept running all night. Chl=4 this morning. Am I reading it correctly? How much MA do I need to get lower the PH to 7.2? I could not figure out how to change the pool volume on the pool math app. Last night I calculated my pool volume supposedly be 44’x20’x8’ deep rectangular= 52xxx gallon instead of the 40000gallon the PB told me.

 

[mknauss]

Use your FAS-DPD test kit for FC testing.

Use the color block for pH testing.

If you are sure of that pool volume (that is very large), go in to Pool Setup (Gear Icon) in the app and change the pool volume.

 

[mknauss]

Last night I calculated my pool volume supposedly be 44’x20’x8’ deep rectangular= 52xxx gallon

Your pool is a consistent 8' deep. No shallow end, no slope, no steps ....

 

[Msch99]

44x20x8 =7040 cu.' x 7.5 = 52,800 gallons if 8' deep end to end.

 

[PoolNewb2020]

Since your PH is above 8, I would recommend bringing it down it steps, especially since you're not sure of pool true volume. I would target 7.8 at first just to see if pool math calculation is correct.

 

[newpoolbuild]

Sorry, my pool shallow end is 3’, gradually down to deep end 8’. My PB ordered 40000gallon of water, the pool was only up to the bottom edge of the skimmer. I had to fill with my tap water over night.

 

[mknauss]

Based on that, with an average depth of about 5 - 5.5 feet depth, your volume is about 35000 gallons.
Start with that figure and see if the chemical additions guide you toward a more accurate number.

 

[newpoolbuild]

How come my pool is 35000gallon if my PB ordered 40000 gallon of water did not fill my pool? I had to use tap water to fill it up to 1/2 way up to the skimmer frame.

Based on that, with an average depth of about 5 - 5.5 feet depth, your volume is about 35000 gallons.
Start with that figure and see if the chemical additions guide you toward a more accurate number.

 

[Msch99]

Either you didn’t get 40k water or average depth is deeper. Once you dial in adding chemicals by changing pool volume to reflect changes in chemical additions you will know a lot closer.

 

[PoolNewb2020]

I would not put too much faith in what your PB said they ordered. Try 35k gallons first in Pool Math, this way if it turns out your pool has more volume, you will not overdose the chemicals.

 

[newpoolbuild]

Which muriatic acid to buy? Anything else need to buy? I went to the store, I got confused,lol

 

[mknauss]

You do not show any muriatic acid in those pictures.
Look for 31.45% muriatic acid. Home Depot/Lowes keeps it outside, in the garden section.

 

[newpoolbuild]

It’s in the last picture. In the Walmart shopping Cart, there’s 2 different kind of muriatic acid. So the liquid kind it’s ok. I was worried since it’s not designated for pool use. Great! I will swing by HD if Walmart doesn’t have it in stock since Walmart has the stabilizer too. Do I need anything else while I am at the store? Thx

You do not show any muriatic acid in those pictures.
Look for 31.45% muriatic acid. Home Depot/Lowes keeps it outside, in the garden section.

 

[mknauss]

Ah -- OK -- that is the Green stuff. It is 20% muriatic acid. It will work, you will need to increase the amount you use versus the 31.45% one.

You will need liquid chlorine. I would guess about 2 gallons of 10% per day until your SWCG is running.

 

[newpoolbuild]

Is there any reason liquid muriatic acid preferred over powder? I need ~2 gallons of liquid chlorine/ day? Mine only contains 7.5% sodium hypochlorite. See pic.

Ah -- OK -- that is the Green stuff. It is 20% muriatic acid. It will work, you will need to increase the amount you use versus the 31.45% one.

You will need liquid chlorine. I would guess about 2 gallons of 10% per day until your SWCG is running.