Can't get it clear

[supermatt9]

I've been using the TFP method on my above ground salt water pool for the last 3 years. The first 2 years it was easy. I stayed on top of it and never had any problems. This year I am struggling. Water has been slightly cloudy since opening and I can not get it clear. Lately it has taken on a slight green tint.

The mystery is that my numbers have always been solid/spot on. Here they are from my last test:

FC: 5.5
CC: .5
PH: 7.6
TA: 90
CH: 80
CYA: 60

Pool stats:
Above Ground
Vinyl Liner
17000 Gallons
Pump run time: 12 hours at 100% generation

I haven't done a slam because my numbers have been right on. But I'm thinking it's my only option at this point. I wanted to come to the professionals first and see if I was missing anything. Could the sand in my filter need replacing (it's only 3 years old)?

Any suggestions?

Thanks.

 

[Texas Splash]

Definitely SLAM, the sooner the better. You see green/tinted water, hit it now. One problem I suspect may have contributed to the issue is your CYA is a bit low for a SWG pool. Not a lot, but perhaps just enough to where your SWG is struggling to maintain that required FC range. So once you complete the SLAM, consider raising your CYA to a minimum of 70 and see if that helps you maintain FC a little better.

As for the sand, it should still be fine, although a deep cleaning might not be a bad idea: Deep Cleaning a Sand Filter

Hope that helps.

 

[RonsPlc]

Correct me if I'm wrong here, but for a salt water system, aren't your TA, and CYA levels a bit low, which would mean that so is your FC?

 

[pooldv]

Doing an Overnight Chlorine Loss Test will always give you an answer on whether to SLAM or not.