Is it normal to have CYA level drop?

[dannieboiz]

So I thought the only way to reduce CYA level was replacing water...

My level has been about 35-40 since forever, but yesterday, when I tested my water it was only 20. So I decided to drop a few puck of tabs in my floaters and slammed the pool.

 

[jblizzle]

CYA is consumed at a very low rate. Plus losses to splashout and backwashing and rain overflow.
And sometimes over the winter it get converted to ammonia and drops to zero, although usually in a neglected pool.

 

[dannieboiz]

that's strange, I slammed my pool a few weeks ago, left it unattended for a week then had algae so I'm slamming again. For the most part, 0I only let my FC dropped to .5 for a few days, beside the green algae on the wall, the water is clear. Could there be something else wrong with the pool?

 

[Propbndr]

The low FC allowed the algae to take off again. You need to repeat the SLAM process.

 

[jblizzle]

Yeah, if you ever let the FC drop below the minimum for your CYA, you could be heading for trouble.

 

[dannieboiz]

Been slamming for 2 days first day i spiked my fc 15 today its at 12.5 im going to let it drop down to 10 and see what happens if needed ill keep it there for a couple days but so far i see no algae.

 

[pooldv]

It is hard to see a low level algae outbreak. It is usually detectable by slimy side walls, filter clogging up faster, higher daily chlorine consumption. Then water gets progressively more cloudy. Then green.

 

[dannieboiz]

Thanks, ill keep an eye out. Can i test cya while slamming?

 

[pooldv]

Yes. PH is the only test that doesn't work with high FC.