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.