CYA levels

[dubbedout]

I just emptied and refilled my 25k Pebble tec pool a few months ago because the CYA levels were so high. Once the pool was filled I used 2 gallons of Leslie's "Instand conditioner" to get the CYA up to around 40-50. I've been using Dichlor (Chlor Brite) and Trichlor tabs for chlorine and my CYA levels have doubled just in a few months. I don't want to have to empty and refill anytime soon but on the route I'm on I will have to. I'm thinking of switching to cal-hypo (Power Powder Plus from Leslie's) to keep my CYA levels from climbing.

Just want to make sure I'm making the right switch. I knew the Chlor Brite was stabilized chlorine but didn't realize that it would make my CYA levels go up so quick.

Thanks!

[BigDave]

What kind of filter do you have? How do you use the tabs and dichlor?

[dubbedout]

It's a Hayward sand filter. I use the tabs in a floater, and the distribute the powder dichlor whenever FC is low.

[BigDave]

If you have no chance of having any dichlor or trichlor in your skimmer, pump, filter, heater, or feeder or anywhere but in the pool, you can slowly dose cal-hypo into the skimmer - it will dissolve on the sand bed and leave it's calcium precipitate there. But Remember - NO trichlor or dichlor anywhere near the circulation system - Cal-hypo and stabilized chlorine have a surprisingly energetic affinity for each other. We don't want your filter to go BOOM after all.

[dubbedout]

I just got back from Leslie's to get my water tested (for a more definite # for CYA). They got a 117 which is pretty close to what I was getting. They recommended staying with the stabilized chlorine rather than switching to cal-hypo. They said the CYA would be fine and that I don't want to add more calcium to the pool.

Full test results:
FC 5.99
CH 275
CYA 117
TA 143
PH 7.9 (I just added 32oz muriatic acid)

[Watermom]

You definitely do not want to continue to use any form of stabilized chlorine. You do NOT want your CYA any higher. Your CH reading is fine at 275. Why not use use bleach? It won't add more calcium nor more CYA.

You also should consider getting a Taylor K-2006 or 2006C (link in my signature below) so you can test your own water. Pool store testing is often not very accurate.

[dubbedout]

I do have a K2006 kit, but I wanted to see what my CYA levels were exactly. Since on the CYA test I lost sight of the black dot right before the water line hit the 100 mark. Maybe I'm just too unsure of my own test results (I'm a new pool owner, just bought this house 1 year ago).

I'm leaning towards bleach now. I was hesitant before having to lug around the plastic jugs as its more convenient to have 50lbs of the granules readily available in the garage. But I've learned that no matter what I use (besides bleach and LC) I'm always going to get something else other than chlorine in my pool...whether it be CYA or Calcium.

I'd like to finish out the remaining Dichlor I have left but don't want to risk raising my CYA any higher. The pool guys said don't worry about the high CYA...I know better. Thinking I'll make a run to Sam's club tonight and grab some bleach. I see they have a 3 pack of 121oz concentrate for about $9.

[Watermom]

Sounds like a good plan. Keep us posted how things are going.

[dubbedout]

Happy to say I picked up 2 cases of bleach last night from Sam's. I used the pool calc to tell me how much to add to raise my chlorine to where I wanted it and it was spot on. Very happy so far. $9 for a case of 3 121oz bottles of bleach ain't bad!

I do have a question thought pertaining to my pH and TA. I used muriatic acid on 6/11 to lower my pH (it was 8.0) and I got it down to 7.4 and the TA also went down from 170 to 140. I've been keeping a close eye on the pH and it's climbing everyday. 6/12 I tested and it was up to 7.6 and today its up to 7.8. I tested the pH of my fill water and its high...at least 8. Am I just going to be stuck with adding acid to my pool every other day?

Thanks!

[BigDave]

The TA will move down as you add acid. The pH rising trend will slow as the TA comes down.