Strange brown spots

Dram414

Member
Sep 24, 2019
7
Texas
All,I have a brand new pool, like 60 days old. After about 5 weeks I started getting these brown spots all over the pool. I have no grass around the pool so it’s not from fertilizer. There are about 300 of them of various shades.

Initially my pool builder said black algae but it’s clearly not algae. My pool guy put a double dose of Algecide in the pool with no change. My pool is maintaining its chlorine which also makes me confident it’s not black algae.

I have had the water tested for everything Ph, calcium, metals and all are perfect. The water is excellent but these spots keep popping up.

I’ve tried muratic acid, lemon, scrubbing, letting shock sit on the spot (actually thankful that didn’t work because it wouldn’t be feasible to do that 300 times)

I have attached pics, any suggestions are appreciated
 

Attachments

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
11,370
Evans, Georgia
Dram, welcome to TFP. I'm sorry its under less than ideal circumstances though.

Are those dots of stain lined up evenly all over the pool, like the first picture suggests? Can you *feel* anything when touching them?

I'm wondering if it isn't some sort of bleed thru from the rebar?? Which would be quite unusual, but to have such stains so quickly is odd too.

Maddie :flower:

paging some good eyes--> @mknauss @Bama Rambler @JamesW
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
9,754
Northern NJ
Metal staining or rebar rusting are my guesses.

Metal will not show in the pool water if it has precipitated out of the water onto the pool surface.

I hope the algaecide added did not contain copper. .

 

Dram414

Member
Sep 24, 2019
7
Texas
I’ll have to check with our pool guy to see the brand of Algecide. The spots aren’t uniformed and they are also on the steps where there is no rebar,the steps were just made from formed gunite.

I checked the copper/iron levels today and there was none. I actually went to 2 different pool stores today and they swiftness water was perfect.

I tried using some vitamin C tablets and nothing.

I am about at my wits end
 

Dram414

Member
Sep 24, 2019
7
Texas
Is the algaecide liquid a blue color?

Do you ever use calcium hypochlorite?
I haven’t tied calcium hypochlorite, what would that do? Is it more of a bleach?

I tested my alkalinity and it was low, I just added 13 lbs of baking soda at the recommendation of the local pool company. They actually tested the water with a centrifuge which was really cool.

I also added some metal out just to see if that works. I tried two different algecides to include Pool Lofe Algae Bomb 30....nothing

Hopefully the baking soda/metal out will work. He spots aren’t growing and the chlorine is stable, no one but the pool builder things this is black algae. The water is totally clear otherwise
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
32,741
Sebring, Florida
Welcome to the forum:wave:

That is not black algae. Not even close.

One of the issues is you are tossing things in the pool to "see if they work" when you have no idea (yet) what the stains are from.

I would suggest you get your own test kit from one of the two we suggest and get your water balanced correctly with your own testing. If you read on this forum much further you will find that pool store testing is ridiculous....no matter how impressive it may seem to you.....it is junk.

While waiting a few days for your test kit, Please read "The "ABC's of Pool Water Chemistry" up in Pool School. That gets you started. Once your test kit gets in and you post the tests that are meaningful, we can help get your water balanced and trouble free.

Alternatively, you can just keep tossing pool store potions into your pool, never knowing what might and might not work but certainly putting things into your pool that you don't need. TFP teaches never to do that.

Once your water is balanced, you can start a systematic approach to getting rid of those stains. Keep in mind I (like everyone else) is just GUESSING but I believe the stains are caused by something you have put in your pool.......putting more stuff in your pool not knowing what will happen doesn't make sense.
 

Dram414

Member
Sep 24, 2019
7
Texas
I have had 3 different pool pros look at the pool and they are all over the place with diagnosis. I did see someone from Louisiana say that they say brown circles around the abalone shell that had been added to their pool (no pics) though. So I looked closely at the pool and I did notice a fair anoint if the spots, maybe 25% are attached to a shell fragment. The others in speculating could have been where abalone shell might have been but flake off.

I’ve had the water tested several times, I was told my alkalinity was down, added about 13 lbs of baking soda, tried metal out, multi spectrum algecide....nada.

Guess I will just bite the bullet and get the black algae cleaner.

It’s strange because a few of the spots came off with muratic acid, others it didn’t do anything
 

JamesW

TFP Expert
Mar 2, 2011
16,342
Guess I will just bite the bullet and get the black algae cleaner.
Bad choice. It's not black algae. Black algae killer is probably copper.

In my opinion, the stain is metal. Probably silver, copper or iron.
 

Dram414

Member
Sep 24, 2019
7
Texas
I went to a pool shop that tested the water in a centrifuge and they only found a trace amount of copper so I added a double dose of metal out. There were no other metals present
 

JamesW

TFP Expert
Mar 2, 2011
16,342
Metals tests are practically worthless.

All water from natural sources contains metals.

I suspect that the algaecide that was used was probably copper or silver.