How to remove Black Buildup on Pool Stairs and dirty Walls

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Hey all, sorry I was gone all last night and missed out on all the "diagnosis".

So, in my opinion, this black has been there all along. In no way have I seen it spread since we started all this adventure (otherwise I certainly would be a bit more of a panic).

There was EASILY 1.5 to 2 feet worth of leaves, murk, sticks (not to mention frogs and a plastic adirondack chair) in the bottom of the pool, and on the stairs. So I am inclined to agree with the idea of leaves just shellacking to the stairs. This was 2 years of neglect. I have felt all along it and it definitely is not slimy or the way it has been described that algae would feel.

Below is a picture of the stairs the first time that we drained it down a few feet. At this point the only thing that had been done was the Dichlor debacle (50 lbs worth - ridiculous). And a bottle of dropoff. At that point, we could ONLY see the stairs and I could EASILY see the black in the same pattern you see now.

stairs1.png


This picture is about a week and a half ago. The previous picture of just the stairs was yesterday. The previous picture of the green (during) was probably 4 days ago.

I am still waiting for my good TF kit to come in (Friday), but based on my latest readings from the kits I do have, I am at about:

pH: 7.4
ALK: 140 ppm
FC: 8 or 9 ppm high, but holding pretty steady
TCl: 2 or 3 ppm (looks right where it should be)
Hardness: really low but I think this is ok in a vinyl pool
CYA: around 40 ppm

From my understanding this is pretty good across the board, and so a very good CC value? I havent had a chance to try any ascorbic acid (vitamen C) to see if any of it comes off.
 
So, some promising news to report.

Mr Clean magic erasers get the vinyl nice and clean, piece of cake (guess I'll just have to jump in and get after all the walls).

walln.jpg


The stairs get a lot better, not all the way, but man oh man does it take scrubbing with those pads, and it destroys them pretty quick

stairsclean.jpg


And the culprit when done

pad.png
 
waterbear said:
2 words--sodium percarbonate
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What is sodium percarbonate and what does it do?

Also, got in to the pool, did some wall scrubbing with the magic eraser, very slow going but it does eventually come off the vinyl walls for the most part, I can go that route, but would doing something like the absorbic acid go alot quicker or work period?
 

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I agree with Waste that the stains are organic. Ascorbic acid only works on metal stains. You can try holding a vitamin C tablet on the stain but I bet it has no effect. However, If you scrub the stain to break up the biofilm, let a trichlor tablet sit on a stain about 30 minutes and then scrub I bet you will see a big difference. Sodium percarbonate is an oxidizer that can remove organic stains in the entire pool. Add 10 lbs of it along with 7 lbs of dry acid (sodium bisulfate) per 10k gallons of water (otherwise the pH will skyrocket). It will bubble and foam. Let sit for 48 hours. Make sure your water is higher than the stain line around the pool. It should take care of the vast majority of the staining with just a little scrubbing. I would brush first to help break up the biofilm and continue to brush during the treatment.
You can buy Proteam System Support if you want a commercial sodium percarbonate product or just order sodium percarbonate from The Chemistry Store.
You can get dry acid at any pool store or big box like Home Depot in the pool section.
 
So I'm curious, are we reaching a consensus or getting farther away?

My inclination all along has been it is not organic in nature.

None of the signs of it being organic have worked, I've tried scrubbing, leaving the tablet, and scrubbing more, with no change whatsoever. Leaving granulated chlorine just sitting on the steps for a long time, etc.

But the magic eraser does get it off with just a bit of elbow grease.
 
I just thought of something else to add, didnt even think of it before.

The pool equipment did include a water heater unit. We disconnected it before starting cleaning and everything because it was no longer functioning.

This could potentially be the source?
 
X1088LoD said:
I just thought of something else to add, didnt even think of it before.

The pool equipment did include a water heater unit. We disconnected it before starting cleaning and everything because it was no longer functioning.

This could potentially be the source?
Click to expand...
Could be but you said that dry acid did not work. Perhaps you did not do the tests properly?

1. hold a vitamin c tablet against the stain (which is underwater--this is important) for about 30 seconds. If ascorbic, citric, or oxalic acid is going to work this will tell you. If there is no change go to next step. If it works do an ascorbic acid treatment.

2. fill an old, white cotton sock with dry acid and tie the top. Fill a small Tupperware container with stones or rocks (we want it to sink and not float) and cover, rubber band the sock to the underside of the container and place on stain (which is under water). Let sit 45 minutes but check at 15 minute intervals. If stain lifts or changes it is not organic and is metal. Proceed to step 4 (sponge test)

3. Take a trichlor tablet, crush it up and put it in a white sock (NOT the one you had the acid in), affix it to the Tupperware container. Brush the stain to disturb any biofilm and place the sock on the stain. Let it sit for 30 minutes. brush well again. If there is any change to the stain it is organic. Organic stains often require quite a bit of scrubbing and an oxidizer to get them off of plastic surfaces. Think of it as a form of mildew (not completely true but there are similarities). You know how hard mildew stains are to remove and they are organic.

4. If step 2 worked the stains are metal and probably copper. The problem is removing them from plastic or fiberglass, which is not easy, since they cannot be acid washed like plaster. Get a bottle of HEDP based metal sequestrant such as Proteam Metal Magic and a cellulose sponge (such as you use to clean the kitchen or bathroom). you will also need your rock filled Tupperware container and rubber bands. Rubber band the sponge to the container and soak the sponge with the sequestrant. Place on the stain. Check in 5 minutes. If the stain lifts and the area under the sponge is back to it's normal color it's metal, go to step 5. If it doesn't resoak the sponge with sequestrant and place on the stain for 15 minutes. If it lifts go to step 5, If it doesn't resoak the sponge and let it sit for 30 minutes. If it lifts go to step 5. IF the area near the sponge turns yellowish at any of these times the stain is organic, go back to step 3 (or use the sodium percarbonate). You WILL need to scrub and use an oxidizer like sodium percarbonate or high chlorine levels (which can bleach a liner--percarbonate is a bit safer but it still can bleach. Think of it like a color safe powdered bleach compared to liquid chlorine bleach that you use in the laundry--it's not but the analogy holds.)

5. Make sure the water level is above the stain line!
If the stain lifted in 5 minutes add one qt. seqestrant per 10k gallons.
If the stain lifted in 15 minutes add two qts. seqestrant per 10k gallons.
If the stain lifted in 30 minutes add four qts. seqestrant per 10k gallons.
Don't try t get away with adding less. It won't work.
The pool will probably get very cloudy for a few days to a week, this is normal. Run the pump and filter 24/7 for about 3-4 days. Check the filter pressure and clean as needed. The pool will eventually clear on it's own. Just let it run it's course. Keep your chlorine levels normal and do not shock while treating and for a few weeks after. This should remove just about all the metal stains.

6. If non of the above work then you are going to have to scrub or replace the stained components. It also means that the stain is organic and the algae or mold has grown into the plastic.
 
frustratedpoolmom said:
This is going to end up being one expensive foreclosure story....
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Not if I can help it.

So, as far as the abscorbic acid, does anyone see where it would be any different to just buy a couple bottles of vitamin C at a pharmacy and crush it up as opposed to the $50 half pound bag at the pool store?

How do I bring the chlorine down (aside from waiting)? Does the polyquat do that or is that just to prevent algae while I am lowering it?
 
The PQ will consume some of it, so will sunlight, and just a couple days of not adding it should drop it fairly quickly.

Right now AA is kinda expensive. The article in Pool School links to a couple sources for AA, probably cheaper ordering it online than a pool store. There are other chems that can do it too, in a thread earlier this week Jason mentioned that Citric Acid is probably the cheapest product right now at $4 a pound.

What I don't know is, is the AA treatment process the same, just substituting Citric Acid?

Anyone?

I was just thinking 'expensive' because the start up (with the pool store), then the water to refill, and now the treatment (not cheap) plus sequesterants to keep the stains from settling again. You have to keep using sequesterant in maintenance doses, because once the stain is lifted, it's back "in solution" and can re-deposit if you don't use sequesterant. That can get expensive. Overtime, as you replace water the metals level will gradually lower, especially if you replace a lot of water to winterize. Will you winterize in Mississippi? Or would the pump run all year?
 

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