Partial Drain - Order of Ops pre-slam?

[PoolStored]

36,600 Gallon Pool in-ground, OHIO.

New to pool ownership. Up until a bad storm, the pool had been fine. Working with local pool store, buying and doing what they told me. After a week with no results (cloudy pool) and constantly fighting my chlorine levels, decided to get edumacated. GLAD TO HAVE FOUND TFP.

CYA = 70...figured out pretty quickly why I'm fighting cloudy pool. Also figured out that I've been pool stored. Have been using Trichlor pucks. No wonder my CYA is so high. Decided that rather than risking SLAM not working at 70, to bite bullet and replace.

Started partial replacement. Poolmath says replace 43% of my water to get CYA to 40. I'm about half-way there (used the calcs to determine to put water in deep end and take from shallow...using pump). All good.

When I'm done with replacement, BEFORE SLAM, what do I need to make sure is right?
a) Ph 7.6-7.8
b) TA 60-80
c) Calcium 50-550
d) Others? Only Ph? Ph and TA?
e) is there some order to add chemicals? Or can I do all at once?
f) how long do I wait after adding to retest?

Thanks for the help!

 

[mknauss]

Welcome to the forum!
Once you are done with your exchange, run the pump for a couple hours, brush the pool well, and then take a sample and run a full suite of tests. What test kit do you have?
Adjust pH to 7.2 with acid and then follow the SLAM Process using the SLAM FC level for your new CYA level.

I suggest you read ABC's of Pool Water Chemistry.

 

[PoolStored]

Thanks for the fast response!
So, pump, brush and sample after a couple hours. Great. Have both Taylor and TF. Learned the testing lesson first from the Pool School!
You indicate adjusting pH with Acid. I think you are assuming pH will be high. This pool has been low and I believe the pH coming in is also low. Likely have to add Borax or Soda Ash to raise. Think I got that right .

I read all the pool school...multiple times. I keep going back as I learn!

 

[mknauss]

Likely have to add Borax or Soda Ash to raise.

Test TA then, If above 50 ppm, be very careful adding chemicals to raise pH.

 

[PoolStored]

Yes, total alkalinity is high, like 110. Still trying to understand the TA/pH relationship and chemicals.

Have a vinyl pool. recommended pH is 7.6-7.8 and TA 60-80. Certainly thinking about aerating, but maybe another week. Or just accept pH at 7.2 (low end of recommendation) until I can get aeration?

I think that I can get pH to 7.2 without much effort, will use poolmath, but if I remember correctly 7.0->7.2 was 4-5 lbs borax.

Now you understand my original question...still working out the relationships.

 

[PoolStored]

As I understand it...Aeration does not lower TA. Dropping the pH by adding acid lowers TA. Aeration brings the pH back up without causing TA to rise. Just to be clear.

 

[mknauss]

As I understand it...Aeration does not lower TA. Dropping the pH by adding acid lowers TA. Aeration brings the pH back up without causing TA to rise. Just to be clear.

Correct. If the TA is high, pH cannot be low, for very long.

 

[PoolStored]

Marty, thanks for the help.

3 day slam so far. Dropped ~2.5 OCLT first night, Dropped ~1.5 last night, hoping tonight it will be done! CC = .4 (25ml test). Pool is cleaner than I have ever seen it. Even dolphin bag...first time I saw ~50% of bag "white" after a day of cleaning. Did behind light and stairs. Lots of brushing. Exciting that this works! Glad I got it done before the 4th.

Put the puckinator in the trash. Stenner pump and tank on the way.

Built an aerator from the TFP recommendations. Next step is TA reduction...now 140...target <90!

Then on to Borates.

Then maintain!

This is my first pool. Glad I figured out that I was getting "pool stored" early in my pool career.

Gave gold donation to TFP. Saved me that much this year in time, frustration and pool store $$.