Am I dealing with Black Algae, Tar, ??

bigpool

0
LifeTime Supporter
Jul 15, 2009
18
Deep South
Thanks to all for teaching me all I do know about my pool. It has been neglected for years. I've gone from 0 FC, high PH, no calcium, scale on the walls, plus green algae and what I think might be black algae. I do have the black circles on the walls but I also have this tar-like stuff in two dead corners, under the ladder, and also in the seams between the wall and the approximate 8" ledge around my big old pool. We have a SWG that just died. We learned it wasn't enough for our 63,000 gal pool and have decided to forget having a SWG and just do chlorine. I hope to get to bleach ASAP.

The good news is I heavy trichlor shocked for about a five days, scrubbed the algae, and I think I'm about balanced. I'm scrubbing the circles with a puck and scrubbing the tar areas with a wire brush. I've left a puck on the tar stuff and can't really tell if it is doing anything. I think digging and scraping it off is all that has really helped. My pool water is sparkling and crystal clear.

I'm just looking for advice about what that tar stuff might be and should I just keep scrubbing until there's nothing left but concrete. It must have eaten the paint. I hesitate to shock again because the water seems so perfect. I am keeping the chlorine (trichlor) high. I've got a fountain going for aeration and just installed a Pool Skim which is a wonderful little jewel. I'm not running the skimmers because I'm still trying to keep the level below the skimmer to patch a leak at the skimmer face plate. Am running the main drain. Like the guy at Leslie's said, there is a lot going on in that pool.

Any advice would be appreciated. I am sincerely trying...

FC 9.5
CC 0
PH 7.4
TA 100
CH 350
CYA 60
Salt 3730
Temp 85
 
Wow, big pool. :wink:

Okay, stop using trichlor today. Go get some bleach. You don't want your CYA any higher than 60 and the trichlor will raise it. So will Dichlor. So at this point, just bleach, and then maintain your FC levels according to the CYA chart (link in my sig). Never let it go below the "min".

Can you post a pic of the "tar" - (it ate thru the paint? :shock: )

So if I understand you the last remaining "problem" is the tar? If you still have the circles, keep brushing them or rubbing with a puck, until they are gone.

What are you testing with? Have you performed an Overnight Loss Test?
 
Yes, that is a huge pool :shock:

You have apparently been working very hard and it shows in your numbers and the fact that your said your water is sparkling and crystal clear :goodjob:

bigpool said:
I hope to get to bleach ASAP.
Ditto to FPM's advice about stopping the use of stabilized chlorine.
Hopefully you can find Liquid Chlorine (higher %) to use or you will be lugging lots of bottles of 6% to take care of your huge pool. :shock:

Here's a thread that may help you decide about the black algae:
black-algae-t13014.html

If your pool is painted, it would be good to add that information to your sig.

You know we would love to see a pic of the 'monster'!
Welcome to the forum :wave:
 
Thanks so much for the response! I appreciate the note of my hard work. My uninterested hubs says I've become obsessed. Somebody had to, the pool was destroying itself and we can't afford the dirt to fill it in.

Have performed the Overnight Test. No loss of FC.

Pool bottom and ledge are painted gunite and I don't know what the painted walls are. I know when I tap on them, they sound hollow. Pool needs painting badly, but don't have the funds at the moment.

Will send pictures of my "tar" and scars as soon as my IT man gets home and can help me with the pictures.

New numbers as of this morning. I am using the Leslie's FAS-DPD test kit and the beloved Pool Calculator you so graciously share. FC is a little high, but I worked in the pool yesterday and my skin didn't peel or anything.

FC 9.5
CC 0
PH 7.4
TA 100
CH 330
CYA 70
OFC Loss = 0
Salt 3730
CSI -.26

Do I need to work on the CYA and TA or just let it ride for now?

Thanks so much for your help!
 
you're only 1.5ppm above your target FC level. many people will swim up to shock level which would be 28ppm in your case.
if you want to lower your cya, you can. my cya is 70 and it's fine. just follow the chart.
I wouldn't worry about TA at this point.
 
Here is the monster, warts and all. Some of the spots you see are where the paint is gone and also where I've been scrubbing. I do have lots of pine trees and fight pine needles in the fall. My PH comes out of the tap at 7.8. I'm constantly adding MA. I'm now wondering can I afford bleach and will it run up my PH?

I was at Lowe's today buying more MA. In the paint section one brand of 20 percent is $5.88 a gallon. Back in the pool section, another brand is 2 gal for $9.98. I'm glad I looked.

Any help is appreciated. I hope the pictures show up.

[attachment=2:4zpiea9b]63k monster.jpg[/attachment:4zpiea9b]
[attachment=1:4zpiea9b]dead corner.jpg[/attachment:4zpiea9b]
[attachment=0:4zpiea9b]under light.jpg[/attachment:4zpiea9b]
 

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could it be fiberglass?
if you can't afford bleach, are you thinking you won't be able to care for the pool whatsoever? I don't know of any cheaper option besides possibly liquid chlorine from the pool store. you don't list your location, but if you call around to some pool stores you can find out (if you haven't already).
the easiest way to tell black algae is it forms a soft slimy biofilm on top that waves around in the water. you can brush it and it will come off easily, but will grow back quickly.
 
bigpool said:
Here is the monster, warts and all.
Wow! It looks great! :goodjob:
My PH comes out of the tap at 7.8. I'm constantly adding MA. I'm now wondering can I afford bleach and will it run up my PH?
No, the bleach is pretty much pH neutral so no problem there.

Are you certain about the gallonage of the pool? What are the dimensions?
Just trying to confirm because less gallons means less bleach/liquid chlorine which means less $$, etc.

Maybe I missed it, but how long have you owned this pool?
 
I do sound whiney, don't I? This pool has been a struggle for 7years. We got the SWG and had a leak we couldn't find so I was hauling in a 40# bag of salt every week. Gallon bottles of bleach amd MA will be childs play. Walmart and Lowe's are just right down the street. I'm thinking I've found the leak and will let the pool evaporate some more before I silicone the heck out of the skimmer face plate and the rope attachment hook. I've spent about $400 in the past month to get where I am, so I don't intend to let the pool go. I'm just looking for the most economical and efficient way to keep things in order. I've been using pucks in floaters for about three weeks since the SWG died and have been shocking with granual trichlor. I just bought 7 gallons of 6% bleach and will see how much bleach I need to stay balanced. If I don't have to shock all the time and add 40# bags of salt, life should be much simpler. We are in need of a paint job, but that will just have to wait for awhile. I was removing a butyl rubber patch from the skimmer cover today and scrubbed a little spot of the wall scale with mineral spirits. It took the white scale right off and underneath was a pretty blue. I'm wondering what would happen if I scrubbed the walls with mineral spirits while the pool is low for repair. Do you think it would hurt anything?

I am in Jackson, MS. Our weather is pretty mild during the winter. Other than fighting pine needles, I think I'll just keep trucking along and not shut the pool down. I've learned a lot in the past few weeks, like you need CYA and calcium. I'd just been throwing shock in the pool when it turned lime green and couldn't understand why it kept happening. Duh.

I have been swimming some. My little fountain makes it sound like my patio is near a waterfall. I just love it. It's like a New Orleans courtyard.

I guess I'll give up on the black "tar" stuff. It apparently isn't eating the chlorine. Maybe I can paint over it when we paint. I had some of the slimey stuff under the ladder. It was gross. I thought at first it was a snake. It is GONE.

Thanks again.

Beth
 

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No, you do not sound whiney! You sound like someone who really cares about her pool and is doing her very best to take good care of it!

Others will be along to chime in on the black 'tar' stuff after they see the pix.

Mineral spirits? Try a google search (bottom left of page). We have several members with painted pools and with different sides/floors materials.

bigpool said:
I have been swimming some. My little fountain makes it sound like my patio is near a waterfall. I just love it. It's like a New Orleans courtyard.
Glad you are enjoying your pool :-D
 
We bought this house (and pool) from my dad about 7 years ago. My dad had terminal cancer and very limited time and my hubs developed heart failure and was supposed to die. Only the hubs had bypass surgery in New Orleans and he lives and works and is doing OK. Needless to say I was a nutcase and the other two were on drugs for their illnesses and pain and we didn't ask enough questions about the pool or the house or anything else. I'm surprised we did as well as we did under the circumstances. Life gets in the way of logic sometimes. Then we started working all the time and here we are. The years just flew by somehow. We just didn't always do what needed to be done about the pool and it didn't just go away.

Hubs says dad said the pool was 63,000 gallons. Dad built the pool so he should have known. The measurements are 25' x 50' x appx 7 ft average shallow and deep. The shallow is around 4' and the deep is 10', so average is about 7'. The shallow end is not very wide and has a large dropoff just past the skimmer. The volume comes to about 65,500 gallons per Jason's pool volume estimator less those little deals in the corners, so I think 63,000 would be fair. I would love to find out otherwise. The pool man who sold us the SWG said we had about 43,000 gallons. The SWG never did generate enough chlorine for our pool when it was alive.

Like I said, I would love to be wrong on the volume. Wouldn't hurt my feelings a bit.
 
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