New 15' AGP - and I might have killed my water. Advice?

[Dougiefreshhh]

Hi -

Been reading a while and I think I might have destroyed my pool water.

Put up a AGP 15'x4' pool (4.6k gals) with sand filter, filled with spring water. Everything was great for 2 months (checked CC, pH) regularly with cheap HD pool test kit (mistake #1)
Was using pucks to keep Cl levels up, but kept finding pH was low (7.2), so kept using pH up to try and get it up to 7.6. Over 2 months probably put in 6 lbs of pH up. Alkalinity was measuring 180ppm. Then read pucks drop pH...ugh...

Pool started to get cloudy, and then we had alge. I had never shocked the pool up to this point. Just used pucks to make sure Cl (TC) was above 3ppm. (1 bag of shock did not do it. So then went to liquid chlorine (12.5%). After 4 gal of shock, the pool is finally blue. The water is still cloudy, but it is getting better day by day (running pump 24/7). Ordered CYA turbidity kit and better FC, CC kit. Also added some dry acid during shocking as the ph went up to 8...per the advice of the pool store. Mistake...again.

Pool store also suggested I add some DE to my sand filter...so read up on that and did that. 48hr after shocking, and once pool was blue, I added clarifyer. Pool is getting clearer, and I am adding aeration to try and get the pH up without adding any more pH up.

As of this AM, this is where my water chemistry is at:

pH - 7.2
FC - over 5ppm
TC - over 5ppm
CC - assuming close to zero..water smells fine..no strong Cl/pool smell, but there is no difference between TC and FC measurements.
TA - 160ppm
CYA - 100

It's hard for me to believe that i have so much CYA only after 2 months of having the pool, and just using pucks.

Other than dumping lots of water, any other suggestions?

Many thanks,
Doug

 

[woodyp]

If the pool store is reporting your CYA as 100.....it could actually be much higher than that with their testing methods. Not much option but to drain about 50%.

 

[Dougiefreshhh]

Thanks. I measured CYA with a turbidity test kit I bought. All pool readings are with my new test kit.

Pool store and test strips said CYA was around 40. Don’t trust it though.

 

[Flying Tivo]

That is exactly why we dont trust poolstore testing. You said you filled with spring water, i would definetly drain and refill at least 90%. Leave a foot of water so the liner does not move. Starting fresh is always best.

 

[jeffchap]

I don't see any reason to drain 90%. A 50% drain will drop your CYA to 50 ppm, which is easily manageable in a pool that size.

Just remember, no more pucks. Only use liquid chlorine from now on.

 

[Dougiefreshhh]

Thanks All. I'm going to dilute my CYA test to get the real number, but either way, its too high. Still can't believe pucks can increase the CYA in a pool that fast.

 

[Dougiefreshhh]

So diluted my CYA test 50% with tap water....reading came out to 60...so my CYA is 120. Now I know I have tons of stabilizer...but should I be running 5ppm FC to ensure against alge, etc...?

 

[MITBeta]

For a CYA of 120, your FC should be about 14ppm. See the FC/CYA Levels.

You probably also need to follow the SLAM Process because the advice from the pool store probably didn't kill all the algae. Lowering your CYA by at least half will make the SLAM Process much easier.

 

[Dougiefreshhh]

Ok. Thanks all. For winterizing I plan to leave the pool up. I will drain it a few inches below the outlets to the pump, and since we don’t have a lot of trees, I don’t plan to cover it. In the spring will add fresh water so I figure that will help my CYA levels.