Water not crystal clear

[d73805]

So, fairly suddenly, my water is not crystal clear. I wouldn't go so far as to say hazy, but it's dull. I can very clearly see the bottom. My wife thinks it has a green tinge, but I think it's because of the blue liner. I'm not sure if I should be concerned.

I don't have my log book with me, so I can't give exact number. These are the approx levels
FC is on the high side, 9ppm
CC is zero, or at least, less than .5
PH is 7.8
TA is up close to 100
CH I don't normally test, as it's a vinyl pool. Should I?
CYA is 70-80
My salt is low, about 2800ppm.

Some other possible useful information
My filters were cleaned about 5 weeks ago. The pressure gauge shows very low pressure.

It recently rained REALLY hard. The water looked great before the rain. The pool level was up close to the top of the skimmer intake. I drained some yesterday. It's now a bit above the middle of the intake port. Maybe it hasn't been filtering properly since the rain?

The bottom return pressure seems very weak, but I've never noticed what it was in the past. Should it be strong? I have strong flow at the jets on the wall, and on the waterfall when I turn it on. Even if I shut off all the other returns, the bottom return is very weak, but I have no reference as to how strong the flow should be.

Any ideas? Thanks.

 

[mknauss]

Check the pH. High pH can make the water look dull.

 

[d73805]

PH is 7.8. It's been pretty steady there all season.

 

[V___25]

Have you done an OCLT?

 

[Newdude]

^^^^ +1. *anytime* you suspect *anything* about non TFP clarity, Overnight Chlorine Loss Test

if you pass we have more time to figure out other possibilities like the high PH as suggested above. Which isn’t it this time, but might be next time.

 

[d73805]

It seems to be getting slowly worse.
I just learned what OCLT means. I turned the chlorinator down to 0, will check the FC now and tomorrow morning. Thanks for the tip.

 

[d73805]

FC and CC are the same between last night and this morning. FC is 7, CC between 0 and .5
The water looks green from an angle but pretty clear when viewed directly from the top. The deep end has gotten pretty hazy.

 

[d73805]

I turned the chlorinator back on and turned the pump speed to 100. I usually run it at 75.

 

[d73805]

Here are some pictures. The clearer close up is the shallow end, the one with the robot is the deep end.
There's a fair amount of some kind of sediment. If I push it with a brush, it comes up like a plume of dust then settles.

My PH was 8.0 when I tested it last night, but my results may be skewed because it was night and I had bad lighting.

 

[d73805]

It's gotten worse. I'm lowering the ph and will start a SLAM. If it's not algae and I SLAM anyway, am I hurting anything?

 

[Newdude]

up to and including SLAM level is safe for equipment and the pool.