TFP Newbie Fighting Black Algae

[Ktmalone]

After receiving questionable advice from neighborhood pool store, I started balancing water chemistry and treating my pool for black algae the TFP way on Saturday. We have thousands of black spots on the bottom of the pool. We brushed spots on Saturday with metal brush and saw green plumes of algae float off. We are keeping FC between 10-15. Most of the black spots are fading to grayish now and we see small gray plumes when we brush.

Questions I have are:
Should we keep pump running 24/7 through this process?
When should we backwash?
Should I shampoo my filter with 'strip Kwik' as pool store recommended?
Am I damaging my pool surface with the metal brush?

 

[northrn]

.....

After receiving questionable advice from neighborhood pool store, I started balancing water chemistry and treating my pool for black algae the TFP way on Saturday. We have thousands of black spots on the bottom of the pool. We brushed spots on Saturday with metal brush and saw green plumes of algae float off. We are keeping FC between 10-15. Most of the black spots are fading to grayish now and we see small gray plumes when we brush.

Questions I have are:
Should we keep pump running 24/7 through this process?

Yes

When should we backwash?

When your filter pressure is 20% above normal

Should I shampoo my filter with 'strip Kwik' as pool store recommended?

No...the pool store hasn't worked so far, right? Liquid chlorine is all you need right now.

Am I damaging my pool surface with the metal brush?

edit: sorry, didn't see your signature at first. someone with more knowledge about that should be along shortly to answer.

 

[Ktmalone]

Sorry, I forgot to post water chemistry:

FC 9
CC 0.5
CYA 34
pH 7.6
CH 230
TA 90
Phosphates 1000+

 

[northrn]

Please forgive me if these are things you have already mastered.

:lookhere: Chlorine/CYA chart Your maintenance FC levels and SLAM chlorine levels are dependent on your CYA level.

You can test and dose every hour if you are available. Hit the algae and hit it hard. Raise that FC 9 to SLAM level as often as possible.

 

[Casey]

Ktmalone, Welcome to TFP.

You definitely have a problem with black algae. You have gotten all that algae because FC was not maintained.

Please read:

ABC's of Pool Water Chemistry
Recommended Pool Chemicals
How to Chlorinate Your Pool
Chlorine CYA Chart

Once you understand the ABC's of Pool Water chemistry, SLAM'ing your pool becomes second nature because you know how it will go and why you are doing it.

SLAMing Your Pool

You are going to need to brush your pool daily to help rid the black algae as you continue to SLAM the pool. It is a tough job that requires a good bit of elbow grease. If your grids are dirty, you can soak them in powdered dishwasher detergent.

 

[Ktmalone]

Thanks so much for your advice. I have been trying to maintaining FC at shock levels for the last two days per your advice and I am seeing improvement which is encouraging. I brushed like crazy last night and FC dropped from 16.5 to 8.5 overnight, so I take that as a good sign. I have not seen overnight FC drops like that since I began treatment. I was confused by the 'black algae treatment instructions' on this site because it says to maintain FC levels between the Target and shock level range.....so I thought any level between would do the job. My pool was neglected while we were on vacation for two weeks and I am paying the price. I am so excited to have found this web site and to say goodbye to the pool store. I have read all the sections you recommended 5+ times in the last week. What a great resource!

 

[Butterfly]

About the brush:

Nylon is for vinyl, fiberglass, tile, and plaster that is less than one year. (Plaster includes any exposed aggregate and marcite finish, btw!) Combo brushes are for older plaster. All stainless are for algae (very stubborn green algae and also the ONLY brush for black algae.)

You CAN unscrew the Wall Whale from the nylon brush it comes with and screw it on a combo brush if your plaster is over a year old. Newer plaster is really too soft for anyting other than a nylon brush.

Welcome to the forum

 

[Casey]

Keep the SLAM up and brushing the pool daily! If you are losing all the chlorine during the night, you've got a lot of algae.

Look at this: Overnight FC Loss Test.

Please post a full set of test results.

 

[Ktmalone]

Thanks so much for the response about the metal brush. That was a big concern of mine.

I did the overnight FC loss test last night. I lost 2 ppm FC.

We were not home most of this past weekend ( Saturday thur Monday) so I have not seen much improvement from last week. We still have 1000's of spots on the pool floor. I was able to maintain FC at the 10-11 range while we were away though.

I am back at it today. I can't believe how hard it is to keep the FC level at 16 (shock level) today. My overnight test dropped from 16 to 14. I have been checking FC every 2 to 3 hours today and adding chlorine each time. I have added 210 oz total from 8am thur 5:30pm. For an example: FC dropped from 16 at 3:15pm to 12.5 at 5:15pm.

Should I increase the FC target level above 16 so I can possibly maintain a 16 average?

My CyA seem to have disappeared. We added CYA last week with a sock in the skimmer and last weeks CYA tests results showed 25-45 CYA. Now CyA is not even 20.

Here are my latest water stats. I'm not sure why my ph and TA went up. We did add 15 lbs of CH over the last 2 weeks to raise it from 170 to 260 so that might account for the ph rise.

FC 12.5
CC 0
Ph 8
TA 120
CH 260
CYA <20

 

[Ktmalone]

I'm not winning. I have been faithfully keeping pool at Slam levels for the past 5 days and brushing with steel brush. I still have thousands of algae spots on the bottom of the pool. Out of desperation I sprinkled di-chlor powder on the top step and after 30 minutes of the powder in direct contact with the algae all the algae was gone.

What is my next move?

FC 17
Ph 8
CYA <30
TA 120
CH 260