CYA Drop

[LFRoberts5]

Why would my CYA levels drop from 27 one week to 9 the next.
I had my water tested at the local pool store and the CYA was 27. I added 2# of Stabilizer to bring it up ran the pump 24/7 for four days. I have been shocking the pool for the last 3 days for an algae problem.
Then when I had the water tested a week later (today) they said my CYA was at 9. Can this be correct? I used a strip test and it confirmed that it was low.
Can someone help me out.
THANKS!

[aylad]

Stabilizer testing is very subjective, and there are a lot of things that could give you different readings. For example, if they're testing via turbidity test, having algae in the pool will usually give a higher than accurate reading. If you're using strips, then shock levels of chlorine can bleach out the test, giving a lower than accurate reading. Depending on how bad your algae problem is, the algae could be degrading the CYA that's in the water, causing the levels to drop.

My advice is to buy a drop-based kit, test it yourself, and dose your pool accordingly. I wouldn't do anything based on strip testing.

Janet

[CarlD]

To build on Janet's accurate statement: When you do your drop testing yourself, you try very hard to do it the same way every time. So even if you are "wrong", you are always "wrong" the same way.

[LFRoberts5]

GREAT!
Thanks for the replies.
Now where can i buy a good drop-based kit?

[stma]

If you don't want to drop $50+ on a test kit, Walmart sell (for $15.99) a 5-way drop test kit that should do you fine for now...just get the one that includes the test for CYA....Just re-enforcing Janet and Carl: ANYTHING is better than the test strips !!

Good luck

[CarlD]

If you have the WalMart kit and are strapped for $$$, you can get just the Taylor FAS-DPD test kit (just tests Chlorine) for about $25