Hard crusty algae on vinyl liner - 2

TommyTN

Member
Sep 10, 2020
7
Knoxville, TN
I have hard crusty (got to be dead) algae on the sides and bottom of the pool. It was yellow algae and I SLAMED it, but it came back. The CYA got too high from using trichlor to slam and I eneded up draining the pool. So then, tap water. Adjusted the balance & SLAMMed it again. It's dead for sure. Scraped some out & put it in a plasitc bucket with balanced pool water & a few dead bugs & got nothing new in 3 days; crust didn't even get soft. During that time, the pool crust mostly didn't change. The the shallow end & sun brightend up, but the rest was unchanged.
So, I saw a post on TFP called "Hard crusty algae on vinyl liner". Fit me to a T, light greenish, tan; scrapes off a little with a fingernail. Brushing does about nothing.
Using muriatic, I dropped the pH in steps. The shallow end cleared up, but the sides & corners of the deep end are still unchanged. The pH is down to 6.0 - that's hard to measure, but pH papers can. (FC is 15+, the muriatic took out the TA).
Never had CH at all - disregarded it - always way low. CYA was 30 before dropping the pH, but but read 0 now - because of pH low?
Anyway, now I I'm thinking new liner.
Can you suggest something?
Maybe I should have tried muriatic on a sponge pole while it was drained?
Thanks for the shoulder.
 

TommyTN

Member
Sep 10, 2020
7
Knoxville, TN
Welcome to TFP :)

I think a picture would be worth a 1000 words here... A brush is not taking it off? How thick is it... never seen nor heard of anything like this...
Well...you have helped me a lot already by asking for pics! So I took some when I was refilling the pool & just took a few more for you. It's working. The comparison of pics shows the stuff is disappearing. TY!
You can see in that corner shot where I brushed on it for at least an hour total - I could see it was coming off slowly at first, but the last couple of brushing made zero haze above the crud. But the photos today 9/16 show a lot more clear area than 7 days ago, 9/9.
Anyhow, after reading about descalers like EasyCare Scaletec and seeing that they take up to several weeks, I think I need to just ask some tincture of time, I hope. But, your opinion is very welcome. What do you think?
What would be nice would be knowing what the stuff is, why it's so attached to the vinyl, what it's made of, and as it disappears - where's it going? In to my pool water, for sure.
( My CH is still 0, so I guess there's no calcium in it?)
Anywho, how do I get that, whatever that dissolved stuff is, out of my water?
TC 0
FC & TC both maxed >20
pH 6.0
TA 0
CYA 0 (but I think that's because pH low. I've put 32 3" trichlor pucks in the skimmers, so there should be 44.3 ppm in the water. I'll stop using up the pucks now & just use bleach when I start to need it again. My CYA target is 50 ppm max in my 24K gallons.)
Wrinkles = 0

Nice car, btw.
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cowboycasey

Gold Supporter
LifeTime Supporter
TFP Guide
Jul 3, 2013
4,104
Fletcher, OK
Tommy, we need you to get a test kit :) Test Kits Compared I recommend the TF 100

And here is why, you say your CYA is at 0, I have an eye opener... Your 32 3 inch tabs of trichlor added the following to your water..

256 oz trichlor = raised free chlorine by 76 ppm = raised CYA 46 = lowered PH by 4.08 and raised salt by 62


I have no idea how long you added the 32 tabs?? a week, a month... Please stop putting them in your skimmer, it is killing your equipment as it is very acidic and plastic does not like acidic...

Lets get a test kit and go from there :)
 
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TommyTN

Member
Sep 10, 2020
7
Knoxville, TN
Thanks for the speedy reply, CowBoy! (Izat car as fast as it looks? You need something like that to outrun all them tornadoes! Bring it to East TN, & drive the Tail Of The Dragon!)
Let's see - I'm using Aqua Test Pool/Spa strips and a Home Depot 5-way Pool Kit, and I've got Leslie's for back-up. Measuring my water to a more nth degree may be a good idea for the future (esp. if i go salt), but I think the main ingredients are pretty clear at this point.
My goal right now, is to get the crud gone, or buy a new liner ~$3K. The super high chlorine & super low pH are doing 2 things - 1. killing any residual yellow algae and whatever else may be growing AND 2. seems to be slowly dissolving the crud, which I believe is dried, dead yellow algae.
Your idea on tab placement is appreciated, but I will rarely be using pucks in the future, .
The pucks were put in as follows:
9/11 - tap water

1st day water up to pump level
9/12 9 am - 14 pucks + 6 oz TradeGrade Phosph remover (poison/oxidizer & food remover)
7 lb - should yield FC 16 cya 23.1 when all dissolved
2pm CH 0
TC 10* - Test Note
FC 10
pH 7.2
TA 40
CYA 0 - but I know it's in there; I think my test strip reads CYA 0 if TC is way high
Leslie's #'s agreed with mine - they couldn't read CYA either & he said because FC too high,
So...I'm SLAMing.
6pm - been sunny all day, but puck have been dissolving normally
CL is 9 -
*Test Note - testing CL > 5.0 with hash marks on CL tube (pic) 1/2, 1/3, 1/4 - fill balance with tap water & multiply by 2,3,or 4. Same with pH - use 1/2 (alkalinity mark), fill with tap, test result x2 or use pH papers.
Not my tricks - Leslie's credit.
anyway, 6pm
Sun's down, time for big SLAM CL
6 pucks + 2 Gallons CL + 9lb BiCarb total pucks now = 20

9/13 9am
CH 0
TC & FC both >20
pH 7.2
TA 90
CYA READS 30 - huh? ok.

9/13 6pm
CH 0
TC & FC both >20
pH 7.6
TA 90
CYA 30

Added 1.7 Gallons acid total
9 pm-the shallow end whitened up a lot!

9/14 9am - pucks are >3/4 dissolved - fast! Acid speeded it up.
CH 0
TC & FC both 24
pH 6.0
TA 0
CYA 0

9/15 9am (old pucks gone) added 12 trichlor pucks total pucks now - 32
CH 0
TC & FC both 24
pH 6.0
TA 0
CYA 0 - I agree with your calculation of CYA 32
two 3" 8 oz (1 lb) pucks Trichlor adds 5.5 ppm FC & 3.3 ppm CYA in 10,000 gallons 5.5x0.6=3.3
32 pucks (16 lb) x 3.3 = 44.8 ppm CYA. The CL should be very high, but it's reducing with the sun & hopefully eating the crud dissolved by the acid, and thebugs, grass, pollen, etc., so it's at 24 for now. I'll keep it there for a week, anyways. That yellow Crud came back once - not again!

9/16 - pictures show much improvement; 90% in shallow end, 40% in deep end.
9/17 - taking more pics for comparisons, but can't see overnight improvement.
Need more tincture of time, methinks.
What thinkest thou, Cow?
You know, I think I may just put the cover on it for the year & let the mixture work all winter.
Open pool 1 month early next year & if it doesn't fix, order a new liner.
I think the low pH may be not great for the liner, but it's fix-it or replace-it time anyway.
The skimmers, pipes, filter, etc. will all be empty, so no hurt there.

Looking back - When it was empty, I should have scrubbed the liner with muriatc or other cleaner that would dissolve the crud. Maybe like LimeAway, used in household plumbing, or some other plumbing solvent.
Looking further back - I didn't realize how much the CYA built up by using Trichlor. Only bleach in the future, but will keep CYA 30-50 using up my old pucks.
Also, I didn't recognize yellow algae & should have SLAMed a lot earlier. 30 years, never had yellow algae; gotta count the blessings.
Looking ahead - changing to SALT in the spring. Let's see what that headache brings. Glad I found TFP! There's guys who've done everything before. This thread has helped keep me organized, too. Also, it's made pool ownership feel like more of a hobby than a chore & THAT I APPRECIATE THE MOST! Good job, whoever thought this up! Nice bit of thinking! What other online schemes have you done?
Maybe I'll even dig in my cheap little pocket & see if I can find a shiny dime for ya'll.
Best Regards
TestKit.jpg
 

Newdude

Well-known member
Jun 16, 2019
4,441
NY
TC 10* - Test Note
FC 10
pH 7.2
TA 40
CYA 0 - but I know it's in there; I think my test strip reads CYA 0 if TC is way high
Leslie's #'s agreed with mine - they couldn't read CYA either & he said because FC too high
CYA test strips have created many a new member here. Often with irreversible problems. Pretty much you have a better chance of licking your wet finger and trying to taste it.

Without an accurate CYA level you/we have no clue how much FC is needed to SLAM or maintain afterwards. It is the most important part of the system.
I think the low pH may be not great for the liner, but it's fix-it or replace-it time anyway
If it goes really low it can wrinkle like a fingerprint, except the whole pool is the finger. Just go in knowing the risk is all.

Keep the thoughts and questions coming. Were here to help
:)
 

TommyTN

Member
Sep 10, 2020
7
Knoxville, TN
Excellent point. I didn't know about the vinyl wrinkling because of low pH &/or high CL.
If you are SLAMing, how long is it ok to keep CL at 15 or better? I've pushed the pH back up to 7 safe enough for now? Thanks again.
 

TommyTN

Member
Sep 10, 2020
7
Knoxville, TN
I took out the last 12 pucks - they were only 10% dissolved.
So my CYA should be 20+1=21 =10.5 lb x 3.3 == ~35ppm
Think it's and emergency to bring the CL down? it's only been 4 days.
 

Newdude

Well-known member
Jun 16, 2019
4,441
NY
If you are SLAMing, how long is it ok to keep CL at 15 or better
If you have an accurate CYA level then it could stay at SLAM level indefinitely with no harm.
I've pushed the pH back up to 7 safe enough for now
That’s another issue. When the FC is 10 or above the PH test is invalid. So the rule of thumb is to adjust it before so it doesn’t go too far during.
 

TommyTN

Member
Sep 10, 2020
7
Knoxville, TN
Thankyou. pH is 7.0 right now with kit, strip, & paper agreeing. I'll just let the FC come on down by itself, then.

Now, if you can make that crud disappear, we'll start a Tennessee whoop-de-do & get out the fruit jar.