60% drained pool & start-up chemicals

watermaverick

Platinum Supporter
LifeTime Supporter
Jun 15, 2010
23
San Antonio, Texas
Hi All

I have a super sub pump and just started draining 3/4 of the pool to reduce the CYA levels - it will be filling in less than 3 hours so I'd like to ask about the new chemicals I put in.

I just received the TF-100 today and already familiarized myself with all the tests on the old pool water.

My plan is to begin with 3 gallons of liquid CYA (with filter running) which I already have...
Wait 24 hours with filter running entire time and then add...
2 qts. of Muriatic Acid (diluted in water first) with filter running - wait 4 hours and then add...
4 gallons of Liquid Chlorine 10% solution and after 12 hours...
test all chems - esp CYA levels which no doubt will need to be raised

I'd like to hear from the experienced ones - thoughts / comments / advice?

Thank you for being such patient people :p
 

coloeb

Well-known member
Mar 13, 2009
226
Wait untill you have a good reading before doing anything like adding chems.
 

watermaverick

Platinum Supporter
LifeTime Supporter
Jun 15, 2010
23
San Antonio, Texas
Finished draining nearly 80% of water from pool (commercial sub pump = 1 hr.) and have been filling for the last 24 hours. I probably won't get a reading until tomorrow morning since the fill won't be complete until tonight. It is hot here so the water is heating up as it fills. Rescued baby frog this morning.
 

watermaverick

Platinum Supporter
LifeTime Supporter
Jun 15, 2010
23
San Antonio, Texas
I'd like some input please - here are my new numbers after draining over 80% of the pool: (these numbers are from the TF-100 test kit)

FC: 1.5
TC: 2.5
CC: 1
pH: 190
CH: 180
CYA: less than the tube can register
Water is clear and clean of debris - color is more aqua than blue

Thank you
 

NCFlyersFan

LifeTime Supporter
May 30, 2008
116
NE North Carolina
You need to check your pH reading. 190 doesn't make sense. Are you sure you didn't accidentally record ALK?

Your first step should be to adjust pH to around 7.2 or 7.4. Next, you have a choice. Either add the liquid CYA to around 40 ppm and shock, or shock first. The reason I say there is a choice is you will need to maintain higher chlorine levels to shock after you add the CYA. Go to pool school and look at the CYA/Chlorine tables to see what FC levels are required based on CYA levels.

Don't forget, you need to shock your pool (i.e. raise and maintain FC to shock levels) until CC is less than .5, your water is clear, and you pass the overnight FC loss test. Pool school has an article that describes the shock process if you are not familiar with it.
 

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