Green pool but no FC movement or CCs

[AndyPTx]

Hi genii! I'm hoping for some genius help.

Reading here for some time - FANTASTIC help through stories and answers. But I can't find one quite addressing this - apologies if there's one out there...

Pool with sand filter here in NE Texas. Clear for ages (you and poolmath). Unbelievably sparkly clear(~er than ever!) (blindingly so when manually vaccuuming!).

Started to feel it looked a tad hazy but had never seen it when cloudy and wondered if that was a factor.

Now it's green though.

At no point ever has FC moved other than feasible by sun or my additions to maintain. But also have had solar cover on except for 2 days/nights last week of July (happened to have a heatwave but often cloudy). Never found more than a possible .5 CCs. Been passing OCLTs.

Now green, but still FC never moves and CCs zero/0.5. Started to brush more when I saw saw patches of yellowish orange on the floor just before haze. Always easily brushed off and clouded up. Brushed like crazy when one morning patches were almost covering the floor. Brushed up under the top of the steel wall and all over steps hard. Everything brushed off. Greenish next day. Now denser green by the day. Not yet fully opaque (or a swamp!).

CC 40 from 50 (rain, evaporation, refill, overflow - 2-3inches was 'changed' water.

pH 7.4 or 5 now 7.2 (before slam)
TA 90 now 7.5
CYA 50 now 40

FC boosted to 18. Never moved, 'til
FC boosted to 20

CCs never more than .5

FC FINALLY moved last night down to 16. Still no change in CCs.

Huh?
Help?!

 

[AimeeH]

Definitely sounds like algae to me. Measuring low CC doesn't necessarily mean you don't have algae present.

Follow the SLAM process. Pool School - SLAM - Shock Level And Maintain

Shock
Level
And
Maintain

You'll need to keep FC up until all three criteria are met (not just one or two)

1. CC are 0.5 or less
2. OCLT is less than 1
And
3. Water is clear.

 

[duraleigh]

FC boosted to 18. Never moved, 'til
FC boosted to 20

Your kit is inadequate or your testing methods are in error. You cannot maintain chlorine in an algae laden pool. Chlorine is consumed by organics in your pool and/or UV from the sun....When you say chlorine "never moved" it just doesn't work like that

 

[Texas Splash]

I agree with Aimee, sounds like algae is trying to bloom. But based on your FC history it would seem odd right? Still, odd tings happen. Other considerations perhaps:

- Deep clean your filter if it's been a while. Deep Cleaning a Sand Filter
- Water circulation okay? Any stagnant areas?
- Are you still using the HTH 6-way noted in your sig, or do you now have a TF-100 or Taylor K-2006?

 

[AndyPTx]

Sorry I didn't make clear I am absolutely in slam process and maintaining 18, now 20 - because edging toward mustard algae level 'just in case'. Is this pointless and just stick to 16-18?

And I guess my real puzzle and question was how it started because I never had FC or CC move (even when brushing up the floor stuff) and yet the sparkly just 'disappeared' into haze, then green one night.

I guess the floor stuff did that, but why for numerous days did it do nothing? How could I stop it if levels acted perfectly, and how can I in the future if it appeared and seemed benign and no levels ever showed a problem?

Stumped.

(Thanks for super-quick reply!)

- - - Updated - - -

Duraleigh - sorry I never mentioned I was using TF-100 testing equipment.

(I am indeed that infamous one that didn't have it before and was using the dilution and tripling 'method'. Ashamed of that now).

 

[Spa Owner]

Its very difficult to post diagnose the cause of an algal bloom. Contributors can include:
- Mechanical equipment issues
- Bird dropping
- Weather
- Fertilizer
- Garden water run off
- Neighbours kid came for swim and didn't clean swimmers transferring some spores
- etc and so on

For future reference as soon as the pool goes hazy is the time to SLAM. The hazy is an algal bloom in progress.

 

[AndyPTx]

Another addition to correct my very misleading comment above - 'FC never moved'. What nonsense! Of course it did.

I meant to say it never moved from sun off to sun on, and moved little otherwise (bubble-wrap cover usually on save for 5 hours of sunshine).

It tended to move maybe at most 2. For that reason (wrongly?) I *sometimes* added only each second day. Sometimes a quart (to add almost 2), sometimes a third of a gallon (to add 2.5).

I still did check it almost daily though, seeing the movement of around 2-2.5 after usually about 2 days, adding either a quart (or once maybe twice just a pint) to maintain 9 or 10 - when CYA was 50 and I was slowly shooting for 55.

 

[AndyPTx]

Thank you again.
As memory serves I bumped up the chlorine a day or two into the haze once I was suspicious enough to be pretty confident I was NOT imagining it due to clouds (and reflections of them or something).

It's bugging me, and concerning me for the future - but I will try to focus on what has become a much more obvious NOW and green, and continue to SLAM away.

Would you object duraleigh if I shared exactly how I have been testing with the TF-100 gear in case you can point out weaknesses or flaws?

 

[duraleigh]

Would you object duraleigh if I shared exactly how I have been testing with the TF-100 gear in case you can point out weaknesses or flaws?

That would be ABSOLUTELY fine! I would add that there are good videos on youtube that show each test but we'll all take a look at your procedures and see if we can help.

Keep this in mind......chlorine in your daytime pool is NEVER stable. It is always deteriorating from one of two things......sunlight or organics in your pool