Can Algae live in pool when passes all 3 tests?

[bkkari]

Hi there,

We followed the protocol and slammed our pool last month for algae. Pool looked great, (aside from a black residue which we wont able to identify.But this eventually went away too). (Also when we turned our SWG back on, it seemed to not ready currently saying our salt level was much higher than what it was: saying 4000-4400ppm when test kits showed around 3500ppm. We're still working on getting the readings correctly, but that's a different forum question.)
Over the last week, we've noticed a few spots on the floor of our pool where it looks like a greenish/yellowish dust. Disappears when we go to sweep/vacuum it up (much like an algae would). It is not on the walls, just along some of the seems and in an area that stuff seems to settle (right before the shallow end changes to deep).

I'm wondering if Algae can still live in you pool, even when it passes the three tests:
OCLT (1ppm last night). CC .5 and water remains clear ?
Or do you think this is possibly something else, like pollen. (I havent been able to touch this substance, because it vanishes when I get close to it).

I have not "slammed" the pool, because I'm not sure if this is necessary, being that we've so far passed the three tests. What do you suggest?

I'm going to test it again tonight to see if any change.


Also another question: When doing the overnight OCLT, do we need to leave our autocover off? (I have, but was just wondering if this was really necessary or not).

Here's our current numbers for our pool:
FC 7.0
CC .5 (this morning)
TA 150
CYA 58
pH 7.8
Calcium Hardness:300
SWG reads 3700 (although test strips show 3200ppm).

Thanks for your response.

Brenda

 

[tim5055]

Can there be algae under those conditions yes, is it common, no. Thinks about it you can have an area of little to no water circulation (think inside a light niche or inside a hollow ladder leg). Algae can grow in there as lone as the water isnt being mixed well, keeping the FC out of that area. That is why during a SLAM you should brush everywhere you can and make sure the chlorine is getting everywhere. So, under some conditions a little pocket of algae can hide out waiting for you to drop your guard. Life gets busy, you skip a couple of days checking/adjusting the pool - My, where did this algae come from...

You have passed all three criteria so i would say not ot a SLAM. Keep your FC where it should be and if there is algae hiding somewhere you will keep it from rearing it's ugly head.

As to your dust, things like that drive me crazy, but in my case it apparently is always pollen or something else that has blown into the pool.

 

[bkkari]

Ok Thanks.
What about leaving the pool cover on night when doing an OCLT? Can I leave the pool cover on, or does this need to be off to get correct results?

 

[jblizzle]

The cover should not matter for the OCLT ... unless there is actually organics on the cover itself (which need to be dealt with anyway).