Name that Algae!

[kiwi_liv]

Hi All,

TRYING to get my pool in shape, except I have these pesky little spots that are appearing. I have 2 in the shallow end, however there are quite a number in the deep end. Good news is that whatever it is, doesn't seem to be spreading anymore. I see there are so many types of algae out there, but how do you know how to treat the algae when you don't know what type it is?! Has anyone had anything similar looking to this and can tell me what it is?

I shocked the water on Friday, but that didn't make a difference. I have since added approx 20oz of Kem-Tek All-In-One Algaecide and that has not made a difference either. I added the remainder of the bottle tonight (10-12oz) but not actually holding out much hope it will do anything. They don't seem to scrub off either (just using my everyday brush) - resilient little buggers whatever they are!

Thoughts anyone?

 

[frustratedpoolmom]

Have you tested the spots with a trichlor tablet or a Vitamin C tablet? Hold the tablet on the stain to see if it fades/vanishes. Trichlor determines if it's organic - Vitamin C determines metals.

Algaecide is really only a preventative - bleach/chlorine is more effective to at killing algae. And just FYI - we only recommend Polyquat 60 algaecide and only in a few specific instances. For the most part in a properly chlorinated pool, algaecide is unneccessary.

Try the trichlor tablet first, see if the stain fades.

 

[kiwi_liv]

I tried the Vit-C tablets (mine are easy swallow, not the chewable type), and it did nothing. I tried my Trichlor tablets and they didnt seem to make a dent either. Should I try different vit-c tablets?

 

[PoolGuyNJ]

What happened if you brush them?

Scott

 

[kiwi_liv]

Nothing at all! They dont move, change color or shape - nothing at all happens! Starting to wonder if maybe it is a stain rather than an algae?! The only things I have added recently is a boat load of chlorine, and pH down.

 

[frustratedpoolmom]

If the trichlor did nothing then they are probably not algae. If the Vit C didn't work, that means it's not iron....
Jack's makes a stain i.d. kit, you could try that.... how long have you been noticing the stains?

 

[PoolGuyNJ]

Are they all green?
Do you have a heater? Test for copper.
Do you have a high water table?

Scott

 

[kiwi_liv]

I will try and look for this stain i.d kit - I gather just order online somewhere? I noticed the stains probably around 2-3 weeks ago. I thought they were increasing at one point, but they certainly havent increased in the last week.

Color - I would say they are more a cream/yellow color.
Heater: no
High Water Table: umm ??? Sorry - no idea!

 

[Guest]

I'm guessing scale. What are your hardness levels?

 

[carolina pool]

It looks like tanic acid which will disipate with time and oxidation.

 

[kiwi_liv]

I tested hardness this morning (only have strips to test hardness) and it came back ok (250ppm).

 

[Guest]

Well, assuming the strips are accurate, that makes me the first loser in the game I hate to lose!!

That is a great CH level, so we will have to see what the real answer (and who the winner) is!!

 

[kiwi_liv]

Ahh yes, but that is the million dollar question - are they accurate?! My total alkalinity from the strips was 40ppm, but my liquid test puts it around 150ppm. I think a trip to the pool store with a sample is in order... but like most things, I dont trust that they arent going to try and sell me a whole bunch of things since I am still learning and dont really know what I am doing

 

[Guest]

Ahh yes, but that is the million dollar question - are they accurate?! My total alkalinity from the strips was 40ppm, but my liquid test puts it around 150ppm. I think a trip to the pool store with a sample is in order... but like most things, I dont trust that they arent going to try and sell me a whole bunch of things since I am still learning and dont really know what I am doing

And that is why it is worth every penny to order one of the test kits and learn how to use it yourself :-D You will be amazed at how easy it is and how much you will learn!

 

[PoolGuyNJ]

Are the spots on the walls or on the floor? or both. If they are on the floor only, what is surrounding the pool within 100 yards/meters?

Are the spots all the same color?

Is there a change in the texture on the spots?

Assuming strips are accurate? Strips are subjective at best.

Scott

 

[kiwi_liv]

I know, I know... I have just ordered a test kit and will be returning the strips today. Just feels a bit like information overload at the moment - I am sure it will all sink in eventually, but until then....

All the spots are on the floor only. There is not really much surrounding the pool - 1 tree from over the neigbors fence that drops a few leaves, but otherwise bare (the garden beds are empty and its mostly pavers surrounding). All spots are the same color, and I couldnt tell you about the texture (I'm not keen enough to jump in and have a look!).

 

[PoolGuyNJ]

I think it's either tanic acid stains which will fade in a few weeks with more exposure to chlorine and warmer water or it's calcium scale. The texture info is important. If the spots are smoother or slightly raised, it's likely scale. Given that the spots are small, a gentle sanding with either a pumice stone or 220 grit wet/dry sand paper will remove them.

Knowing your chems are right will help prevent this.

Scott

 

[carolina pool]

If we get a second guess, maybe wayward fertilizer or an iron supplement added to the garden.

 

[kiwi_liv]

Thank you all for the incredibly helpful input - I will be sure to let you know the 'winner'

 

[chem geek]

Test strips do not measure Calcium Hardness (CH). They only measure Total Hardness (TH) which includes magnesium in addition to calcium. They also only resolve to around +/- 40 ppm and can often be less accurate than that.