Helping a friend who has been pool store'd


LifeTime Supporter
Jul 9, 2011
My friend has been going to a pool store for years. She has been using something that has obviously been adding cya. The store keeps telling her to shock, and then sells her cal-hypo(notice the CH results). I don't think she has every actually got the pool to shock level.

I went to her house with my kit and here are the results.

Fc .5
Cc .5
Tc. 1
Ph 7.8
Ta 250
Ch 450
Cya 100+

Help me make a bbb convert.



LifeTime Supporter
Jul 9, 2011
She is doing that today. So when she fills it back up I guess we test cya again and then begin the shock process if CYA is reasonable?


Well-known member
Jul 4, 2011
Perrysburg, OH
Remind her to be patient! A pool like that is going to take a while to clear up. Stay strong - she'll probably want to convert back the old pool store ways after a couple days...


LifeTime Supporter
TFP Expert
Jun 5, 2012
DFW, Texas

What is the pool surface of your friend's pool (plaster, vinyl, fiberglass, other???)? I'm assuming the pool in your signature is for your pool, not your friend's. Reason I ask is, since you are doing a partial drain & refill (D&R) mainly for CYA, you may also want to test the CH during this process. Plaster pools require some CH (ideally 250-350 ppm). However for vinyl and fiberglass pools, the CH should be kept at lower levels. If the pool has either a vinyl or fiberglass surface, try to get the CH below 300 ppm while you are doing a partial D&R. Would hate to see you complete the D&R, then get the pool in shape and later discover that the CH is still too high for the pool's surface. That would require another partial D&R to remove the excess CH.

Click the Pool Calculator link in my sig for target levels of CH for the pool surface type as well as for CYA (pool surface doesn't matter for CYA). The thing to remember about CYA and CH is that it is much easier to add these chemicals if either amount is lower than your target than it is to get rid of them if either amount is too high.


LifeTime Supporter
TFP Expert
May 10, 2010
SW Louisiana
With a vinyl liner you never want to drain too low, you always want at least a foot of water in the shallow end, otherwise the liner may lift up and wrinkle.