Yellow/Mustard Algae SLAM Problems CYA, PH, FC, Dichlor HELP

[Fadderall]

Thank you all at TFP! Best Pool Site Ever.
I converted to TFP method years ago, after the pool store merry go round had me draining and refilling pool (after only 2 years) to lower CYA. All was great until my laziness got the best of me and I stopped testing and just threw chlorine in until it looked good. Last year and a half I have seriously neglected the pool.

Now, I am trying to get back on track and need your help again. I opened the auto pool cover (pool being covered all the time is probably only thing that saved me from swamp) and found a huge amount of yellowish growth on the pool wall shady side. After looking through TFP determined that it should be Yellow Mustard Algae. I have had this before in same spots but it has always gone away with a few days of balanced chemicals or just adding chlorine. This time there is also a ring around the pool at water level that is yellow and green. There is also loads of the stuff inside the skimmer spillway and at the bottom of the spa spillover. All shady areas. But, this time it is going no where so I started a SLAM.

Problems I have had for a long time:
PH always seems to want to stay high >8
TA always seems to want to stay high >150 (I have done the Acid and Aeration method to reduce but always goes up)
CYA biggest mystery to me. Since drain and refill I have never been able to get CYA to register. I have used the liquid gold nature stuff and the granules in sock in skimmer method but never seem to get results.

Starting SLAM measurements
FC 0
CYA 0
PH 8++

Raked, brushed, vacuumed the pool, cleaned cartridge filters, pump on 24/7.

Brought PH down to 7.6
Used Dichlor (Leslies Chlor Brite) 1lb bags to start chlorination and quickly raise CYA.

DAY 1 (evening)
3lb Dichlor (to raise CYA by 18 and FC by 20 supercharge)
PH 7.6
FC 19
CC 1

DAY 2
6:35am Water murky, Brush, no change in appearance of Algae.
FC 16
CC .5

7:30am Water murky, Brush, no change in appearance of Algae.
FC 15.5
CC 0

8:30am Water murky, Brush, no change in appearance of Algae.
FC 15
CC 0

9:45am Water murky, Brush, no change in appearance of Algae. Realized I have been doing FC test from memory and only adding 1 scoop 0870. all further tests with 2 scoop 0870.
FC 12.5
CC .5
CYA 0-20 (test water cloudy but dot visible all the way to top of tube).

11:15am Water improving, no change in appearance of Algae.
FC 10
CC .5

12:30 Water improving, no change in appearance of Algae Added 1lb Dichlor (now 64oz total should be CYA 24)
FC 8
CC .5
PH 7.8

1:30 Water improving, brush, no change in appearance of Algae Added 16oz Muriatic Acid to bring down PH added 32 oz 10% liquid C
FC 11
CC .5

4:00 Water crystal clear, Brush, no change in appearance of Algae. Added 32oz 10% liquid C
FC 12
CC .5

DAY 3
7am Water crystal clear, Brush, no change in appearance of Algae.
FC 11
CC <.5
CYA 20? (still fill to top of tube but much harder to see black dot then before.

I will retest PH as soon as FC is below 10 and adjust if necessary.

QUESTIONS
CYA seems to be going up. Should I add another 2lbs (32oz) Dichlor (one 1lb at a time) to raise CYA above 30?
Is it normal that I cannot see any change in the visible Algae yet?
Is it normal that brushing seems to have no effect on the Algae? The brush doesn't make any marks in the Algae and it doesn't seem like anything gets brushed down or into the water (no clouding or residue from the brushing).
Should I do a TA, CH or other tests?

In addition to the Algae I have a stain across the bench in the deep end. The infloor cleaning system shoots dirt up onto the bench and whoever designed neglected to put cleaners on the bench so it just sits there. I let it go for a long time and I think that it is dirt on the step that has dug into the plaster. Brushing has no effect anymore. See pictures. Is this also Algae or dirt? In either case, how would you suggest I tackle this issue as well?

THANK YOU IN ADVANCE!!

PICTURES OF ALGAE
SHADY SIDE WALL

CLOSE UP SHALLOW END STEP SHADY SIDE WALL

EXTREME CLOSE UP SHALLOW END

DEEP END SHADY SIDE WALL

DEEP END BENCH I ASSUME IS DIRT ATTACHED TO PLASTER BUT NOT SURE. IS THIS DIRT OR ALGAE? HOW DO I GET RID OF THIS?

 

[Fadderall]

UPDATE
9:15am
FC 10.5
CC <.5

12:30pm 4 drops R0005 to 7.2 ADDED 1.15qt Acid 29%
FC 8.5
CC <.5 (trace)
PH 8

Plan going forward - Retest PH ~1 hr until 7.2
Add 16oz Dichlor again to raise chlorine and hopefully get to 30 CYA and FC12

Anyone have any thoughts to my previous questions?
Also, just noticed that the Acid I put in says 2x stronger then supermarket/home depot type. Label says 29%. What strength is assumed in the Taylor Acid Demand Table? Did I just add double what I was supposed too?

 

[Fadderall]

UPDATE 2
Had to wait longer to test but.
4:00pm Brush
PH 7.6 3 drops 0005 to 7.2 Added 1.72 pt Acid as per taylor chart
Added 1lb (16oz) Dichlor (Leslies Chlor Brite) to increase CYA hopefully above 30 and to boost FC to shock level again.
Didn't test FC since I am running very low on 0871 (should have bought the -C 2oz as recommended, you guys are always right) more coming tomorrow.
I will Test FC this evening and CYA and retest PH in the morning when below FC 10

Water is still crystal clear. Algae will not come off the side walls. I never see any grey or dead algae and all my brushing and scrubbing seems to have no effect. Is this normal? Do you think this is actually yellow Algae or something else? I also never see much of a rise in CC which I thought would indicate that the FC is eating or killing the Algae, is this true? CC seems to always be less than .5 (sort of pinkish that dissipates after one drop) but I am doing the 10ml test to conserve 0871 now. I would say that CC is <.5 or trace usually.

PLEASE any help or guidance would be very much appreciated. Am I doing things incorrectly?

 

[kellyfair]

With all that you have done to try and budge it, I have to wonder if this is algae. You aren’t able to budge even a smidgen if you try to scrape off with fingernail?

 

[Fadderall]

Good idea. I just went out to try and scrape some of that part in the shallow end. The stuff on the plaster would not scrape off with my thumbnail but that plaster is really rough so it may just be that my nail is not getting into the rough texture. On the tile right next to it I could scrap the stuff off but it did not feel slimy or gooey like I would expect Algae to feel. It was like scraping a calcium deposit kind of hard and scaly.

I do wonder now is this in fact yellow algae or something else?

The pool water BTW is pristine right now, but that wall stuff aint going away.

 

[mknauss]

Have you tested CH and TA? Have you been using any algaecides or other pool store potions? Anything with 'Blue' in the name?

Do you have a record of all the products with CYA in them you have added and how much they should have raised your CYA?

 

[cfherrman]

Start using bleach now that you should have 30 cya and slam for 30 cya.

Search here for the puck test on the stains to see if their organic stains

Keep brushing, vac to waste the solids if you can

 

[Fadderall]

Have you tested CH and TA? Have you been using any algaecides or other pool store potions? Anything with 'Blue' in the name?

Do you have a record of all the products with CYA in them you have added and how much they should have raised your CYA?

mknauss - I just tested TA last night.
TA 230
Its high but always seems to be high in my pool. Have not tested CH but with Las Vegas water it will be high.

NO POOL STORE GARBAGE. No algecides or anything with "blue" in it. The only thing I have added from pool store is Leslies Chlor Brite which is Dichlor from what I understand (if I am wrong please let me know). I did this to quickly raise my CYA to 30. It was zero when I started.

I have added 5 lbs (80oz) of Dichlor (not all at once) so far. According to pool math for my 10,000gl pool should get me to 30 CYA. I plan to test CYA again today to confirm.

 

[mknauss]

OK -- so your CSI is most likely very high. And I bet the 'algae' is embedded in scale and cannot be attacked by the chlorine. Have you managed the water in the past to maintain a 0 or slightly negative CSI? You mentioned it being covered, was the pH and TA maintained during that time?

I use the same water you do (Colorado River water) so we must be very diligent about CSI. I manage my water until the CH reaches 1000 ppm and then drain and refill.

If the pool is scaled up then an acid wash will remove it. But it will also degrade your plaster. It might be time for a re-plaster.

Take care.

 

[Fadderall]

Start using bleach now that you should have 30 cya and slam for 30 cya.

Search here for the puck test on the stains to see if their organic stains

Keep brushing, vac to waste the solids if you can

cfherrman - I had not heard of the puck test for stains. If I understand it correctly I just hold a puck on the stain for a few minutes see if it has an effect? Is there another way to do this? Maybe a cup of bleach held over the spot? Do you know if I can buy 1 puck from the store? LOL. I will try this today.

Yes on the bleach. That was the plan as soon as I get the CYA up to 30 confirmed.

 

[mknauss]

Walmart or even Home Depot sells individual pucks. At least I have seen them in the past.

That is a good test to try. But if it is embedded in the scale, it may not get to the algae.

 

[Fadderall]

OK -- so your CSI is most likely very high. And I bet the 'algae' is embedded in scale and cannot be attacked by the chlorine. Have you managed the water in the past to maintain a 0 or slightly negative CSI? You mentioned it being covered, was the pH and TA maintained during that time?

I use the same water you do (Colorado River water) so we must be very diligent about CSI. I manage my water until the CH reaches 1000 ppm and then drain and refill.

If the pool is scaled up then an acid wash will remove it. But it will also degrade your plaster. It might be time for a re-plaster.

Take care.

No, I have never managed CSI (had to look it up to see what you meant). Ashamed to say that I have not been trying to manage TA for a couple years and have not paid attention to PH or TA for the past year.
I do get the white calcuim build up on the tile along the water line.

Is an acid wash something I can do myself or does it require special equipment? Does pool need to be drained?
Did you see the picture of the bench in the deep end? It looks to me like embedded dirt. Do you think an Acid wash would fix that as well? Does the acid wash smooth the rough plaster or do I need a re plaster for that?

Oh and on my TA test I used an extra drop of thiosulfate since I was at high FC levels and wanted to make sure it neutralized. Would this effect test results?

Thanks so much for the help.

 

[mknauss]

You must drain your pool to do an acid wash. I suspect you need to any way as your CH is most likely very high.

It is a somewhat dangerous process so trained personnel should do it.
I suspect the embedded dirt, etc is in the calcium build up on your plaster. An acid wash dissolves the calcium (and some of your plaster!).

How old is the plaster? Do you want to start over and truly manage your water chemistry? There is no way you can run a pool with our water chemistry and not manage pH and TA. Unless you plan to replaster every few years.

The TA test should be OK.

 

[Fadderall]

You must drain your pool to do an acid wash. I suspect you need to any way as your CH is most likely very high.

It is a somewhat dangerous process so trained personnel should do it.
I suspect the embedded dirt, etc is in the calcium build up on your plaster. An acid wash dissolves the calcium (and some of your plaster!).

How old is the plaster? Do you want to start over and truly manage your water chemistry? There is no way you can run a pool with our water chemistry and not manage pH and TA. Unless you plan to replaster every few years.

The TA test should be OK.

Pool is about 7 years old. Yes I do want to manage the pool properly again. I think I have learned the hard way what happens with neglect.
That being said, I'm not sure I have the budget for a replaster. Is that what you are suggesting?

 

[mknauss]

The issue is an acid wash will compromise your plaster. At 7 years and having been neglected from a chemistry standpoint, you may be replastering very soon after an acid wash.

You might try calling some companies that acid wash and see what they say. But I would start planning to replaster in the fairly near future.

Take care.

 

[cfherrman]

Look into a no drain acid wash and a zero ta treatment

Longer/harder to do, but safter

 

[Fadderall]

The issue is an acid wash will compromise your plaster. At 7 years and having been neglected from a chemistry standpoint, you may be replastering very soon after an acid wash.

You might try calling some companies that acid wash and see what they say. But I would start planning to replaster in the fairly near future.

Take care.

Thanks for the advice. I will call around. I saw a few companies that claim they can sand down the plaster instead of acid wash. What do you think as far as what would hurt plaster more? Also, some companies claim they do a chlorine wash. Do you think that would be effective?

THE BIG QUESTION-
Is this just something unsightly at this point or does it pose a health issue? If I SLAM the pool completely according to the 3 end point criteria (CC <.5, overnight OCLT and water clear), then raise to the Yellow mustard FC shock level for 24 hours, will it then be safe to swim in the pool even if this staining is still on the walls? Or, is there still a risk with it dug into the calcium/plaster?
If I cant afford to plaster until the fall or winter can the kids still use the pool this summer or will they get sick?

I just ran full tests to see where I am at.
FC 10.5
CC 0
PH 7.8-8 (used 2 drp thiosulfate to neutralize chlorine so may not be accurate. It was 7.6 yesterday at 4 and I added almost a quart of acid at that time.)
CH 390-590 (not sure on this test. Turned purple at 39 drops and kept getting bluer. After 59 drops I could no longer detect any more blueing of the solution.
TA 230
CYA 25 ( I hate this test. Seems I can always sort of see the dot. I have watched video and looked at sample images. Back to sun glance at tube. I am sure it is over 20 now but probably not 30 so I call it 25)?

Thanks again.

 

[mknauss]

I suppose it could be ground off. You will need a complete drain and refill no matter what you do to remove the calcium.

Chlorine wash is useless. A SLAM does the same thing.

As long as you maintain your FC at target level for your CYA the water is sanitary. May not be aesthetically pretty.

Take care

- - - Updated - - -

Your CH is based on the 59 drops from your explanation. So about 1500 ppm

 

[Fadderall]

Look into a no drain acid wash and a zero ta treatment

Longer/harder to do, but safter

I just looked at that but seems I need to bypass my heater and I dont think I am plumbed for that. I think I need to do a full drain refill anyway (as per mknauss) to get rid of the calcium build up.

- - - Updated - - -

- - - Updated - - -

I suppose it could be ground off. You will need a complete drain and refill no matter what you do to remove the calcium.

Chlorine wash is useless. A SLAM does the same thing.

As long as you maintain your FC at target level for your CYA the water is sanitary. May not be aesthetically pretty.

Take care

- - - Updated - - -

Your CH is based on the 59 drops from your explanation. So about 1500 ppm

Thanks.
To note I did the 25ml test which I think is multiplied by 10 so that would mean 590 ppm CH. Do you still think I need a drain refill?

 

[Fadderall]

Got a new picture really close up of the stuff on the walls. Any ideas what it is? Algae? Algae in calcium?

Also, any confirmation on that CH test? You said 1500 ppm but I think that is with the 10ml test. I did the 25ml which says multiply by 10 so 590. Or, did I get this all wrong?

If it is 590 do I need to do a drain?

full size link IMG 7680 — imgbb.com