From blue to green - all values fine

[jokael]

Our pool has been tfp-clear until yesterday. When I pulled the cover off, it was yellow-greenish. The bottom had a lot of yellow dust - the pump is running 24/7

Cya: 30
FC: 6.5
CC: 0 (maybe 0.5 - very hard to see a difference)
TA: 80
PH: 7.6

The pump is blowing out yellow clouds, too small to be caught in the skimmer sock/nylon stocking.
Could it just be pollen? And how to get rid of it when it just passes through the filter?

 

[mgtfp]

Any pollen you can see settling on surfaces?

I'd start with an OCLT to rule out Algae.

If not Algae, you can try to add DE (pool grade, not garden or food grade) or cellulose fibre to your sand filter to assist filtering of finer particles:

Add DE to a Sand Filter

A clean pool filter will increase the efficiency of your pool! ... your filter are to backwash it, clean the manifolds and grids, and add new DE.

www.troublefreepool.com

 

[jokael]

Any pollen you can see settling on surfaces?

I'd start with an OCLT to rule out Algae.

If not Algae, you can try to add DE (pool grade, not garden or food grade) or cellulose fibre to your sand filter to assist filtering of finer particles:

Add DE to a Sand Filter

A clean pool filter will increase the efficiency of your pool! ... your filter are to backwash it, clean the manifolds and grids, and add new DE.

www.troublefreepool.com

The oclt is 1
I have absolutely 0 cc - that is strange.
No pollen on surface.
I bumped fc up to 18 yesterday afternoon. At night it was 17. This morning 16 and I topped up to 18 again as we have a very high uv-inden today and I was away for some hours.
There is no change in colour from yesterday - that puzzles me, since my last slam showed a noticable difference overnight.
There is no more yellow blowing out. A backwash was almost neon yellow in colour………..so the filter catches a lot.

 

[mgtfp]

From 17 down to 16 over night is not bad. You're a bit above SLAM (12 for CYA 30), zero over night loss would be unrealistic there. Could be pollen.

I'd keep FC a bit elevated and keep filtering.

While FC is elevated, you can use a 5ml sample (unless doing an OCLT) which will give you a resolution of 1ppm/drop, to save your precious reagents. If you don't have a 5ml graduation on your test tube, you can use a syringe to measure the right quantity.

 

[mgtfp]

CC is more a result of FC oxidising bather waste (sweat, urine, etc) rather than algae. And pollen is pretty unimpressed by chlorine, also no CC creation there.

 

[jokael]

From 17 down to 16 over night is not bad. You're a bit above SLAM (12 for CYA 30), zero over night loss would be unrealistic there. Could be pollen.

I'd keep FC a bit elevated and keep filtering.

While FC is elevated, you can use a 5ml sample (unless doing an OCLT) which will give you a resolution of 1ppm/drop, to save your precious reagents. If you don't have a 5ml graduation on your test tube, you can use a syringe to measure the right quantity.

Thanks for the tip on the 5 ml sample. When I have FC this high, of course there’s no need to measure .5 values during the day
I know I’m a bit high with my cya of 30, but with our high uv-index today, I would rather go safe than sorry
And I’ll keep filtrering and say “PoP”