Opened up pool and I have black algae again.

Connie C

Silver Supporter
May 16, 2019
11
Strasburg, Ohio
Opened up pool and I have black algae again. We had it last year and it's there again. Should I drain and powerwash it? We haven't done anything except take cover off.
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
10,174
Evans, Georgia
Connie, please don't make me have to look up your zip code to figure out where you are? Just put a location. Thanks!

Are you sure this is black algae and not just algae that looks dark?
What did you do to get rid of it last year?
How do you sanitize your pool?

Can you tell us:
FC
CC
pH
TA
CH
CYA

and which test kit you use?

Thanks in advance-
Maddie :flower:
 

Connie C

Silver Supporter
May 16, 2019
11
Strasburg, Ohio
I am in Strasburg Ohio. I just took cover off. Haven't tested or started anything up yet. Ordered a new test kit per advice of this site, tf test kit. I am not sure if it is black algae. A ton on skimmer bottom but the rest of the pool looks like residue.
 

Connie C

Silver Supporter
May 16, 2019
11
Strasburg, Ohio
Last year I did the shocking brushing and used the black algae product the pool co sold me. I am trying to attach pics. I use chlorine powder from pool place but ready to switch this year to bleach
 

Attachments

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
10,174
Evans, Georgia
Ah, ok.... that sounds more promising than the dreaded "black algae"... That stuff actually grows roots into cement and all that.

Ok... while you wait to get that kit, figure out where you can obtain the most fresh liquid chlorine/bleach for the least cash and hassle.

And go ahead and do you best to gently scoop out any solid debris in the pool because if its there when you start to SLAM you'll waste a lot of energy on it.

Maddie :flower:
 

Connie C

Silver Supporter
May 16, 2019
11
Strasburg, Ohio
Connie, please don't make me have to look up your zip code to figure out where you are? Just put a location. Thanks!

Are you sure this is black algae and not just algae that looks dark?
What did you do to get rid of it last year?
How do you sanitize your pool?

Can you tell us:
FC
CC
pH
TA
CH
CYA

and which test kit you use?

Thanks in advance-
Maddie :flower:

Hi Maddie
FC .05 more like 0
CC 0
ph 6.8
TA 80
CH 300
CYA 20 can still see dot
 

Teald024

TFP Guide
Are these TF-100 test results?

For the CYA test, was the test cloudy at all? If so, add 20ppm CYA. If test was totally clear, then add 30ppm CYA. Add the CYA to a regular sock and hang it in front of the return. Make sure it doesn't touch the wall. Leave the pump running 24/7. Just to confirm, the pool water was room temperature when you did the test?

pH needs to be raised. You can do this with aeration and it is chemical free. Aeration can be done via spa jets, waterfall, fountain, return pointed up so it breaks the surface, air compressor, etc.

Once you have the sock of CYA in the water, add enough chlorine to get to 10ppm FC. Test and re-dose with chlorine often. Brush and vacuum the walls and floor daily to allow the chlorine to get to all parts of the algae.
Follow the SLAM procedure.
 

Connie C

Silver Supporter
May 16, 2019
11
Strasburg, Ohio
Are these TF-100 test results?

For the CYA test, was the test cloudy at all? If so, add 20ppm CYA. If test was totally clear, then add 30ppm CYA. Add the CYA to a regular sock and hang it in front of the return. Make sure it doesn't touch the wall. Leave the pump running 24/7. Just to confirm, the pool water was room temperature when you did the test?

pH needs to be raised. You can do this with aeration and it is chemical free. Aeration can be done via spa jets, waterfall, fountain, return pointed up so it breaks the surface, air compressor, etc.

Once you have the sock of CYA in the water, add enough chlorine to get to 10ppm FC. Test and re-dose with chlorine often. Brush and vacuum the walls and floor daily to allow the chlorine to get to all parts of the algae.
Follow the SLAM procedure.
Yes they are TF100 results. It was not cloudy at all. I did it twice but it was not room temp. I had taken it out of cold pool. I will get CYA tomorrow. I don't have that. I am assuming pool store. Is my pool sweeper ok to put in water as well while cya is in there and heavy bleach? Sorry I am not savvy I went to a pool store for years and just did what they said. Hasn't worked out so well and a lot of money wasted.
 

Fast7

Well-known member
Aug 8, 2018
64
Plainfield, IL
Did you drain your pool recently? Your test results indicate you have almost non existent CYA which is usually thru the roof after years of disinfecting pool with pucks or pool store dry type shocks.
Add some liquid chlorine to your pool ASAP.
 

Teald024

TFP Guide
CYA can be found at the PS or Walmart. At Walmart, it is sold in 4 pound containers in the pool section. That is usually good stuff to use.
Walmart also typically has a good deal on their 10% chlorine in the pool section. check pricing for singles vs multipack. sometimes one packaging variety is priced better. Check date codes such as 19XXX. With 19 being the year of manufacure and XXX being the day number of the year. Get the most recent chlorine you can find.

A slight modification to my advice provided above. Before you add the CYA, I would like you to run a test. Add enough chlorine to the pool to get to 10ppm, in front of a return with the pump running. 15 minutes later take a sample of pool water and run a FC & CC test. If the FC is above 5ppm, then add the CYA. If FC is below 5ppm, then report back to us for additional advice. The 15 minute interval is important (don't wait hours).
 

Connie C

Silver Supporter
May 16, 2019
11
Strasburg, Ohio
Did you drain your pool recently? Your test results indicate you have almost non existent CYA which is usually thru the roof after years of disinfecting pool with pucks or pool store dry type shocks.
Add some liquid chlorine to your pool ASAP.
We have drained it the last two or three years because it has been a mess. That's why I am finished with the pool place. I did add the liquid chlorine and borax. Looking beautiful. I added the CYA Tuesday and everything looks good for the moment. My cya is now a 40. ph went from 7.6 to 7.2. Unsure why. fc is really high on the tester 5-10
 

Connie C

Silver Supporter
May 16, 2019
11
Strasburg, Ohio
CYA can be found at the PS or Walmart. At Walmart, it is sold in 4 pound containers in the pool section. That is usually good stuff to use.
Walmart also typically has a good deal on their 10% chlorine in the pool section. check pricing for singles vs multipack. sometimes one packaging variety is priced better. Check date codes such as 19XXX. With 19 being the year of manufacure and XXX being the day number of the year. Get the most recent chlorine you can find.

A slight modification to my advice provided above. Before you add the CYA, I would like you to run a test. Add enough chlorine to the pool to get to 10ppm, in front of a return with the pump running. 15 minutes later take a sample of pool water and run a FC & CC test. If the FC is above 5ppm, then add the CYA. If FC is below 5ppm, then report back to us for additional advice. The 15 minute interval is important (don't wait hours).
I didn't see this in time Monday. Looking good now. Did add the CYA.
 

Connie C

Silver Supporter
May 16, 2019
11
Strasburg, Ohio
You stated you have a TF100. Always use the FAS-DPD (R0870 and R0871) to test your FC.
I am sorry I did use the FC tester. That was the ph and chlorine test. My new readings are as follows:
ph 7.2
cya 40
ta 80
FC 5.5
CC 0
Is this good or should I be worried if my ph is a little low? the CYA was added two days ago and stayed the same yesterday and today. PH also stayed at 7.2 two days.
 

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