Can I have algae growth without CC?

[Kev68ss]

I have noticed, what I thought was dirt, some slippery light brown slimy stuff, that brushes easily-some sort of algae- It's a pretty new pool but here are my numbers-

Salt water Pool, vinyl, 27,000 gallons
80 degrees
1.5 TC , 0 CC - Has been holding strong at around 3.5 in our hot 95 degrees days- getting a lot of rain lately though. I turn my Autopilot off from 10 pm till 8 am. From there its on high spd till 6p, then low speed til 10. Maybe I should run pump 24/7??

180 TA- (I know, working on it)
7.8 PH- Just added acid
CYA- 40 (working on getting it to 70)

I didn't think algae would grow with 0 CC, but obviously it can- verified with TFT-100 test kit FAS-DPD

I just threw in 3 jugs of bleach, and 3 qts of acid, and 6 pounds of CYA

 

[JohnT]

Yes you can have algae without CC. Usually with low FC like you had.

 

[257WbyMag]

The presence of CC is just an indicator that chlorine has combined with organic contaminants. One can have a green pool in any degree, with or without CC.

 

[dchan]

Yes you can have algae without CC. Usually with low FC like you had.

I have a similar situation.
FC 6
CC 0
CYA 50
PH 7.2

Water has turned slightly green the past few days, with some green deposits on my steps. Overnight FC test shows no noticeable drop, and CC remains between 0 to 0.5. Test results were taken with a TF100 kit I bought last week. To be safe, I've started the shock process, but curious as to why no CC and no measurable overnight FC loss.

 

[chem geek]

Are you sure it's algae and not pollen (or metals, though you said you saw deposits on the steps and your pH isn't high)? Pollen as well as dirt can sometimes not show CC nor overnight loss. It depends on the quantity and type of pollen since some doesn't react with chlorine very quickly. Take some of what you have on the steps and put it in a jar of pool water and have it outside in the sun -- cover it with cheesecloth if you've got a lot of pollen in the air. If it's algae, it should continue to grow in the jar (especially if you put a tiny amount of fertilizer in it) though at some point when the chlorine drops you could get real algae growth but that might look different than what you are seeing. If you have a microscope, you can look at the substance that is on your steps -- algae is semi-transparent and often oblong in shape while pollen is usually round and solid in appearance and sometimes has spikes.

 

[dchan]

Pollen and dirt sounds like a good possibility. It has been really windy the past 3 days so a lot of leaves and debris have fallen in the pool, especially bay leaves with a sticky residue. I've skimmed and brushed every evening, but I'm sure plenty of junk is getting into the water. I dont have a microscope, but will try the jar test if more deposits appear on the steps.

Tested the water again this evening and still no significant FC loss or CC levels. But the water has become a darker green. I've boosted FC to 20 with Clorox bleach.

 

[dchan]

Oh, and even though the recommendation here is that phosphates dont matter, I went ahead and added Phos Free since I had it sitting on the shelf. Bought it and a bunch of other stuff before I went to Pool School.

 

[chem geek]

If you do have phosphates in the water, then the phosphate remover may make the water quite cloudy. PhosFree might have a clarifier in it to help clear such cloudiness; otherwise if you get cloudiness that doesn't clear up you may need a clarifier as well -- one of the downsides of using a phosphate remover.