black \ green \ brown dots in the pool

LeeM2

0
Jul 3, 2010
96
Sorry for double posting, but I'm really concerned with this issue and I don't now who else to turn to.
I've purchased the house this year. The pool is about 5yr old.
I didn't have any of these dots when I opened the pool, had about a dozen a couple of weeks ago but now I have a lot more of these. I don't know what can be causing this. I've been shocking weekly with calcium based shock up until beginning of July (not because my FC was low, but because I was advised to do so as a good practice) and now my CH is about 600. The rest of the parameters look good. MY FC loss is about 1PPM overnight.

Could high CH be causing this? I also added PhosFree, Instant Conditioner about 1-2 months ago still use Leslies tablets ( because I want to get rid of some while my CYA is 30-35, PH 7.6, TA 130). Can any of these chemicals be responsible for this?

I tried rubbing them with chlorine tab, tried Vitamin C tablet - neither works on brown\green ones. I managed to get rid of some black ones with chlorine tab though. Some of these feel like bumps, (like they have heads), others are flat. Maybe the brown ones are flat, not sure

Please advise. Thanks
 

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simicrintz said:
Looks an awful lot like rust to me. How old is the pool (or finish)? What product is your finish?

Pool is about 5 years old.

What product is the finish - how can I tell? I may have some papers from the company who built the pool, will have to check if it's there.

Also, I didn't have these when I opened the pool. I started noticing them about 3-4 weeks ago.

If it is rust - where is it coming from and what do I do about it? Occasionally I see some brown dust in the pool - could it be rust?

Thanks.
 
The finish looks pretty recent, so I assumed ( :oops: ) that you selected it and may have remembered what it is.

Sometimes the finish covers some rebar or tie wire in the pool that is too close to the surface. After a while, water gets through to it and it starts to rust. It slowly works its way to the surface and shows itself. If you can find out what the product is, there is a good chance they can patch it.

Here's a couple other options, both of which I have seen: It could be iron from fertilizer, if you have recently fertilized. I have also seen kids shooting bb's in the air and/or throwing them in pools. That might also be something to consider.
 
I don't fertilize. I have these spots everywhere, on walls, floors, steps. They are not just in one spot - they are everywhere.

I just wonder if it has anything to do with the way I maintained the pool or it's just a coincidence and not uncommon for 5yr old pools. One thing is certain - I'm getting more and more every week. Before I had to dive with camera in water proof case to take a picture. Now I can do close-ups with dslr because I have plenty of these dots to chose from

I tried a crashed chlorine tablet and crashed vitamin C yesterday. No changes. I wonder if there's something like a pencil, which I could use to treat all these dots one at a time, while I have *only* a few dozen of them.
 
How long did you hold the tablets on the spots?
I wouldn't crush them I'd just hold them on the spot for about 10 minutes. If that doesn't change them try 30 minutes.
They really do look like rust so I'd probably try the Vit C tablet first but that's just my personal preference.
 
You stated a chlorine tab worked on some - and since they weren't there before and are getting more frequent, it seems organic to me.

This surface is 5 years old correct? How often do you brush the pool?

Make sure you are brushing the pool at least weekly. Especially brush these spots with an SS brush (since the surface is 5 years this should be safe). If this is black algae - and a chlorine tablet worked, brushing knocks off the outer shell allowing the chlorine to get to the inside. Keep your FC levels slightly elevated above 'normal' and brush alot. See if this makes a difference.
 
Chlorine worked on black dots, didn't work on the green\brown ones.

*It does seem like the brown ones are green at first and then once the outer shell gets removed the spot becomes brown*. I have to verify this is the case though.

Good point about brushing. I stopped brushing my pool once I got rid of all visible algae about 1,5 months ago.

Is this the type of SS brush you were referring to? - http://www.amazon.com/Dayton-2ZTY2-Algae-Brush-SS/dp/B001QRFI3K

I believe leslie's have this one for $20 in-stores - http://www.lesliespool.com/browse/H...ire-Brush/D/30100/P/1:100:3000:300000/I/20146

The dots are about 1-2mm in size and there are probably 1-3 per sq ft. Would it make sense to go with smaller brush? Any particular one you'd recommend?

Thanks.
 
The Leslie's brush ought to do it.

It's wierd that they are changing color. How did you remove the outer shell? Have you tried rubbing a tablet on the spots, not crushing them? Have you tried rubbing them on the spot after the shell you described is removed?
 

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frustratedpoolmom said:
The Leslie's brush ought to do it.

It's wierd that they are changing color. How did you remove the outer shell? Have you tried rubbing a tablet on the spots, not crushing them? Have you tried rubbing them on the spot after the shell you described is removed?

I didn't remove outer shells. The green ones have shells, but browns don't and I assumed that they become brown once shell gets removed. I'm yet to verify if that's the case though.

I tried rubbing with a piece of tablet (the small piece from the floater) for about 30 seconds or so on brown, green and black ones. It only seemed to work on black ones. I rubbed them until they are covered in chlorine. Should I try to rub them longer? Is Leslie tablet what I need or some other tablet that dissolves faster (hth?) would be better for it?
 
Melt In The Sun said:
Honestly, to me it looks like you have some pebbles in your finish that are iron-bearing and are rusting. If that's the case, you can either live with it or chip it out.

but if that was the case, wouldn't vitamin C get rid of the rust? I crashed vitamin c and put it in the sock on top of the brown spot for about 20-30 min. I also tried rubbing the vitamin C tablet against it, didn't do a thing.

Also, I used to have may be a dozen of these, but a week later a have a few dozens. I'm just afraid that my pool will be all brown the next season.
 
Are you still getting more spots everyday? If you were to leave one spot alone would it grow or just stay the same 1-2mm?
Did the dots show up after you stopped shocking? If thats the case I would keep shocking weekly. At least until the fine people here get your problem figured out.
 
I was thinking along these lines:
- A vitamin C tablet will remove a very thin layer of iron stains very quickly. If you have a thick crust of rust, it may remove some, but not all, and thus appear that it didn't have any effect.
- The fact that they are uniformly distributed suggested to me that it was something in the finish, since I would think black algae would tend to form first and fastest in areas of poor circulation.
- Now that you're looking specifically for these spots, you're finding more of them. They could have been there all along, and you just overlooked them. I've done the same thing in my pool; once I got a pair of goggles, the condition of my finish got a lot more scrutiny.

Beyond that, I'm stumped too. Just explaining my though process....
 
Melt In The Sun said:
- Now that you're looking specifically for these spots, you're finding more of them. They could have been there all along, and you just overlooked them. I've done the same thing in my pool; once I got a pair of goggles, the condition of my finish got a lot more scrutiny.

Beyond that, I'm stumped too. Just explaining my though process....

No. Before I had to dive deep with water proof camera case to get the picture. Now they are on steps, just 5" below the water level
 
frustratedpoolmom said:
Yes if the spots were iron the Vit C would remove it.
I'm stumped.
I assume you aren't shocking weekly anymore (cuz you really don't have to...)
What do you keep your FC at daily?

I was shocking weekly with calcium shock and then I didn't for a couple of weeks and shocked again with liquid because I found some algae hiding behind the light cover. I opened the cover, wiped the lamp and all algae ended up on the pool floor so I shocked again. I can't say if shocking has anything to do with it or not. My FC is always above or around 4ppm and CYA is 30-35 according to my tests.
According to 2 Leslie stores, where my water was tested yesterday (after it was shocked) my FC is 5 and CYA is 60. If leslie's CYA test is more accurate then mine, then my FC level may be a little low. I'm not sure why leslie's test for chlorine shows 5 when it was above 10 on my tests. I didn't pay attention how they test things, but maybe their chlorine test only goes up to 5 or something.

I'm going to try wire brush this week and report back on how it goes. I didn't brush my pool for over a month and I really hope it's algae.

Is there a reliable way to test CYA, other then the one that comes with TF100? Is there a chance my CYA testing tube is inaccurate and needs to be replaced? I only used it 3-4 times, but maybe it had to be dried out after each use?

Thanks.
 
Shane1 said:
Are you still getting more spots everyday?
It seems like it. I don't swim every day, but when I swim I find new spots.

Shane1 said:
If you were to leave one spot alone would it grow or just stay the same 1-2mm?
It'll stay the same. I just get more of them, but they all are about the same size, 1-2mm.
Shane1 said:
Did the dots show up after you stopped shocking?
If thats the case I would keep shocking weekly.
It may seem like it, but I can't say for sure. Again, according to my tests my FC level is always at it's target. According to Leslies, it may be at minimum or even slightly below minimum. I'll probably start bringing it up 1-2ppm above then target at night. This should insure that I won't go below minimum FC during the hot day and also may account for the possible CYA of 60.
Can you damage anything by over-chlorinating your pool by a couple ppm when using liquid chlorine\bleach?
 
I tried the wire brush on that spot on the picture for about 20 minutes - nothing. I just held the brush head, without a pole and tried all directions. It didn't come off, didn't get smaller.

What should I try next? Are there any chemicals that I should try?

Thanks
 

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