Sick of Algae!

jdfreeman

Well-known member
Jun 23, 2024
61
Northeast Louisiana
Pool Size
26400
Surface
Vinyl
Chlorine
Liquid Chlorine
I've been fighting algae in my pool since April and I found TFP a few days ago. I've declared war on algae and I'm ready to have crystal clear water in my pool. I bought a Taylor K-2006C kit and it arrived this morning. Tested my Ph first and it was over 8.0, the color of red was darker than the highest reading. I tested CYA and it was over 100, maybe 120? Tested my FC and it looks like I have 29 ppm chlorine. I'm ready to SLAM but the first step is to get Ph to 7.2. How do I achieve this? I have a partial bag of Ph minus which is 92% sodium bisulfate. On a side note, I've added liquid chlorine to my pool the last two days just trying to increase the chlorine level and get a jump on it. I have a 30' round above ground pool which is about 26.5k gallons. Any help would be MUCH appreciated!
 
Don't use pH minus, adds sulfates which attack metals and concrete. Use Muriatic acid.

pH test is invalid when FC is above 10. I would not adjust pH based on your current results (FC being high)

Before you do anything, you need to get your CYA down. Do the diluted test at #8 in this article and report back.


You will want to exchange some water in the pool with a high CYA. Read no drain water exchange here:

After you do the diluted test, we will figure out how much to exchange...
 
Ok, I did the diluted test again per #8 in the article and now I'm reading about 98 to 100 somewhere in there.
Unfortunately, before I ready your reply I went ahead and put 2.6 pounds of ph down in the pool. I got a little overzealous. I'll be reading the water exchange article and report back after lunch. Thank you so much for your help!
 
Dilute it twice and test again...1/2 pool, 1/2 tap, mix, dump half. add tap again, mix, dump half, then add reagent, your CYA is likely over 200.
 
Ok, I did a dilution 1/2 pool and 1/2 tap like I did before and got the same result, about 100. I diluted it twice like you described above (which I think should be 25% pool and 75% tap?) and I came up with about 61-62.
 
Ok, so your CYA is 240. You will need to replace 80% of your pool water to get CYA down to 40-50. What kind of pool is this? What is the volume?

Any CYA north of 90, you cannot keep enough FC to sanitize the pool. Anything north of 60 CYA is a VERY tough SLAM.

Read up on the no drain water exchange I posted. Exchange 80% of your pool water.

When complete, do not use pucks or Dichlor shock...both add CYA. Your high CYA is due to the use of these products. You will need to use liquid chlorine, or get a salt water chlorine generator.
 
Thank you very much. I have a 30' diameter above ground pool. We've had it for 4 years and never had this problem. My wife wanted the pool and we had an agreement that if we got the pool, she would be responsible for maintaining it. We live in north Louisiana and our pool is out in the open so we have never covered the pool and it's always been great. However, this past winter, my wife let the pool get algae and turn a dark green. She's been trying to get it corrected since it started warming up in April. It is blue, we can see the bottom, but she has not been able to get rid of the algae. We've put 50-60 plus bags of shock in the pool over the past 3 months. I have decided to take over the pool maintenance and once and for all get rid of the algae and have a clear pool. That started with a good test kit, which she didn't have. She's been using test strips even though I told her to get a good kit. I received the Taylor K-2006C kit this morning and I'm ready to attach this pool!

So, draining an above ground pool - I'm going to drain to waste through the pump, but once it gets below the skimmer, how to you keep draining? This may be covered in the water exchange article but I'll read again. I didn't see it on my initial review. Thank you again for your help!
 
Don't use the pool pump. A moment of inattention and you are below the skimmer, you will burn up the pump. You either get a sump pump, or you can rent a trash pump from HD if they have a rental center near you.

It's all in the draining article. Print it out and read it a couple times.

What is the brand and product name of the shock that you were using?
 
I've got a sump pump going right now. Pump is off but turned to waste. The shock my wife bought was from Sam's Club. Quick dissolving shock is what it says on the box.

So do I just pump out about 80% of the water and eyeball it? Then start refilling with fresh water?
 

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Ok, so by my calculations, to drain my entire pool of 26k gallons, it's going to take about 44 hours. 80% of 44 hours is 35.2 hours. That will take me into the early morning hours of 28th which is Thursday. Does that sound right?
 
Ok, so by my calculations, to drain my entire pool of 26k gallons, it's going to take about 44 hours. 80% of 44 hours is 35.2 hours. That will take me into the early morning hours of 28th which is Thursday. Does that sound right?
Yes. Is there a reason you don't want to do an exchange?

Did you read my note about the 12-18"?
 
I’m willing to do the exchange, no problem there. I didn’t think it would take a day and a half. I want a clear pool and I’m willing to do whatever it takes. I just wanted to make sure that was normal. Yes, I saw the 12”-18”, I won’t take it down past that level. I’m down past the skimmer now, it’s been going about 3 hours.
 
Yeah, I think mine took about 32 hours...it is a slow roll at 5-6GPH.

You will never have a clear pool with the level of CYA you have in the pool. There is no getting around that fact.
 
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I really appreciate the help. This is a learning experience for me and we won’t be using shock or chlorine tablets once we get this under control. I’ve got 15 gallons of liquid chlorine and I bought 3 gallons of muratic acid today. Once I get fresh water back in the pool I’m assuming I’ll start the SLAM process. Is there anything else I need to buy to get ready to SLAM?
 
15 gallons of LC is fine, you can always return it, or use it to chlorinate. 3G of muriatic, if we get you fixed up is likely a lot. No worries, it is fairly cheap. I don't think you will need anything else for the moment.

Measure the TA of your fill water. Post results.

Great job, by the way!

You got this!!!

You Got This Good Luck Today GIF by MOODMAN
 
The draining is going faster than expected. I’m about 24” or so from the bottom.

I tested the TA of my fill water and I think it’s 280-320. I’m not sure when to stop the drops. When it started to turn pink I was at 28 drops. I continued to 36 drops but after about 32 drops it really didn’t change to a darker pink. Not sure how to read that.
 

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