1st Time Slam Questions

May 15, 2015
10
Boise, ID
I'm trying to ditch my pool supply store and do it myself...but I'm having questions. My water is clear, but there is yellow algae on the bottom of the pool...not a ton, but it's definitely there.

Here's my results when I started yesterday:

ph 7.4
FC .5
CC 3.5
CYA 40

I've been adding GALLONS AND GALLONS of bleach in the last 24 hours (probably almost 18 gallons). The highest I've got the FC test to read was 6 (this morning). I added 2 more gallons and checked 2 hours later. The FC was down to 4. So, I added another 4 gallons (always 8.5% bleach) and tested 1 hour later and the FC is .5. Am I doing something wrong? I'm about to head out to the store and buy another 20 gallons of bleach. Thanks for any help you can offer!!
 
Did you start with CYA 40 or did you add CYA to get there?

Did you read the article about the SLAM process?

http://www.troublefreepool.com/content/125-slam-shock-level-and-maintain-shockingl

Pool Math will tell you how much bleach to add. Starting at 0 FC you would be adding 652 oz all at once. I guess that's about 5 1/2 bottles of 8.25%. Brush the pool, especially where the algae is visible. Give it an hour and test your FC again. Use Pool Math to,tell you how much to to get back to add to get back to 24. Keep doing that as often as possible. The more times a day you test and adjust back to 24 the quicker things will go.
 
Did you start with CYA 40 or did you add CYA to get there?

Did you read the article about the SLAM process?

http://www.troublefreepool.com/content/125-slam-shock-level-and-maintain-shockingl


Pool Math will tell you how much bleach to add. Starting at 0 FC you would be adding 652 oz all at once. I guess that's about 5 1/2 bottles of 8.25%. Brush the pool, especially where the algae is visible. Give it an hour and test your FC again. Use Pool Math to,tell you how much to to get back to add to get back to 24. Keep doing that as often as possible. The more times a day you test and adjust back to 24 the quicker things will go.

I was at about 20 CYA last week and I added CYA to raise it to 40.
Yes. I've read the SLAM articles and lots of related forum threads.

Ok...I'm confused...why are you saying I need to get it to 24? Based on the CYA chart for a level of 40, I thought I had to get the FC to 16. Am I mistaken???

I've been brushing and adding chlorine like you said. 2 hours ago I got FC 10 and CC 2. I added one gallon and tested 1 hour later. Now my readings were FC 9 and CC 2. I added 2 more gallons.

I feel like I'm on the right track now, but now I'm questioning my "target" FC.

Thanks so much for your help!!!
 
I just wanted to say welcome to TFP! And add are you sure the yellow is algae an not pollen? I only ask because this seems to be a high pollen year.

Yes I think I'm sure. I had the same issue last year. I would vacuum and it would disperse the algae and then "magically" it would appear the next day. I was cleaning off my cartridge filters every single day and they were just getting caked in algae. I wasn't doing a great job maintaining the FC level and I was listening to too many pool-supply salesman...buying expensive stuff that didn't work. My pool was new last year and I didn't know what I was doing...I didn't even realize it was algae...I just thought my pool was getting strangely dirty each morning. Ahhh, live and learn! I'm determined to use the TFP system this year and save myself a bunch of headaches!
 
Ok...I'm confused...why are you saying I need to get it to 24? Based on the CYA chart for a level of 40, I thought I had to get the FC to 16.
you are correct, I had the wrong number in my mind while typing. If you "never" get to 16 maybe there is another issue. Old bleach or your pool is larger than you think are the first two that come to mind.

But, I still think my original thought is correct, you are not adding quite enough. When you were at 10 you say you added a gallon, then tested an hour later. At 10 you should have added 217oz of 8.25% to get to your target of 16. That is just shy of 2 bottles (8.25% comes in 121oz bottles) and I probably would have just gone ahead and added two.
 
Yes I think I'm sure. I had the same issue last year. I would vacuum and it would disperse the algae and then "magically" it would appear the next day. I was cleaning off my cartridge filters every single day and they were just getting caked in algae. I wasn't doing a great job maintaining the FC level and I was listening to too many pool-supply salesman...buying expensive stuff that didn't work. My pool was new last year and I didn't know what I was doing...I didn't even realize it was algae...I just thought my pool was getting strangely dirty each morning. Ahhh, live and learn! I'm determined to use the TFP system this year and save myself a bunch of headaches!

I am glad tou found us and can now take care of your pool. Sorry it is definite algae but we are here to help. If you have questions just ask.
 
Ok, I've been at this for days...am I doing something wrong?? I've been using SOOO much chlorine. My pool is crystal clear. The water hasn't ever been cloudy. Skimmer baskets are empty. Filters are "clean" according to the filter gauge. During the day I open the pool to add chlorine then I brush and close the cover to block sunlight. Why am I still consuming so much FC? It looks like I'm still loosing at least 1 FC per hour (even at night). I want to give up, but I know that I can't and there MUST be something the pool is still fighting. Is this normal? Is there an end in sight? Here's my numbers for the last couple of days:

CYA 40-45
Shock level 16-18
(I know I've gone way above shock level but I was concerned that maybe I hadn't read my CYA correctly, and I've also read about certain algae that can only be killed at FC 24, so I thought I'd try to get it up higher than my shock level--maybe I shouldn't do this??)



Sunday FC CC Add chlorine?
9:44pm 19.5 2 no

Monday FC CC Add chlorine?
7:00am 12 3 4 gal
10:50am 20.5 2 2 gal
12:00pm 26.5 2 no
2:40pm 20 0.5 no
3:50pm 20.5 1.5 1 gal
6:15pm 22 1.5 no
8:15pm 20 1.5 2 gal
10:45pm 22.5 .5 no

Today FC CC Add chlorine?
7:00am 13.5 1.5 3 gal

The one good sign I see is that there is no more visible algae. I used to see it every morning on the bottom when I would open the pool, then I'd vacuum it up. Now I haven't seen any for days.
 
I'm going to guess that the reason you have higher CC is your pool cover. While UV consumes FC chlorine, the pool needs exposure to UV to burn off the CC also. Leave the cover open and I bet those CC's will go away.
 

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I'm so FRUSTRATED!!! I've looked for algae everywhere I can possibly think of. I have no ladder and I've scrubbed my lights and returns. Two days ago I thought there might be algae in the filters, so I opened them up and yes, they were caked in algae. I hosed all four of them off and was hoping it would be the end of all my troubles...but my numbers still aren't good. I'm still loosing 1FC an hour on average. My pool "looks" great. Crystal clear water, no algae on the bottom when I open in the mornings...just bad numbers. Here's my last 3 days (CYA 40-45)

Numbers are FC/CC/gallons bleach added
May 22
8:15am 15.5/ 1 /2
12:15pm 17/ 0.5 /0
3:45pm 14/ 0.5/ 2 (here's where I found the algae in the filters and cleaned them off)
10:15pm 13.5/ 0.8 /3
12:00am 23 /0.8 /0

May 23
8:15am 16.5/ 1 /2
12:15pm 21/ 0.8 /0
5:00pm 18.5/ 1.2 /1
10:20pm 14.5 /1 /2

May 24
8:00am 14 /0.5/ 2
12:30pm 16.5 /0.8 /2
5:00pm 17.5 /0.5/

Please help!!! I've been at this for 10 days and I've probably used 100 gallons of bleach by now. I'm at my wits end.
 
A SLAM is a process that takes time and lots of POP aka pool owner patience.
All SLAMs vary as to how long they take. Mine took 13 days. There are others who have taken a month or longer. Just keep doing what you are doing. You will get there.

The thing I notice with you current readings is that even when you are at 17 you are not adding anything. I would target 20 and even if you are only 2 ppm low, still add bleach to keep you at or above SLAM level. Each time you drop below its slows the process.
 
Thanks for talking me off the ledge :) I can keep going as long as I know this is somewhat "normal" for it to last so long. My big issue is having kids who want to start swimming. I know it's safe to swim up to shock levels, but if I'm slightly above, am I putting them in danger?

You are right...as I look at my numbers I'm letting it drop below shock level frequently. I guess I have another question: Assuming your shock target is 20, what would you try to keep it at if you don't want it to fall lower than 20 (since I can't be constantly monitoring every hour). What is "too high"?
 
No problem. I hear you whe it comes to the kids. If you are below SLAM level then it is fine to swim. If they swim above SLAM level they could get chemical burns from the high FC. My daughter asked me daily if she could swim. I told her to be patient and then she can swim everyday.

I would just target 20 since that is slightly above your SLAM level. Don't let it drop below 17. When you add in the morning you could target 22 to account for the loss of FC to the sun if you cannot test in the middle of the day.
 
I passed!!!!:D:D:D:D

I wanted to give up so many times and I appreciate the encouragement I found on this forum. It took 16 days (which is 15 days longer than I thought it would take:) ) . 100+ gallons of chlorine put into the pool but now it looks amazing! I am so determined to never let my pool get out of hand again, and now I feel much more confident in my ability to care for my pool. Thank you thank you to all who helped and for this great forum of information!
 
Hold the phone! Last night when I performed my OCLT, the FC was 20.5. When I tested at 8:00am this morning my FC was 20.5 and CC was .5. I figured I had passed! I went out tonight to test to see if my kids are safe to get in the water now and the FC is down to 11.5!! We've tested 3 times so I know the results are accurate. I did leave the cover off all day and it was very sunny ( I was trying to bring the FC down a bit to safe swimming levels). There is also a lot of cotton in the air and I know it's been getting in the water. Could sun and cotton bring the FC down that fast? Now I'm concerned :( Advice??
 
Hold the phone! Last night when I performed my OCLT, the FC was 20.5. When I tested at 8:00am this morning my FC was 20.5 and CC was .5. I figured I had passed! I went out tonight to test to see if my kids are safe to get in the water now and the FC is down to 11.5!! We've tested 3 times so I know the results are accurate. I did leave the cover off all day and it was very sunny ( I was trying to bring the FC down a bit to safe swimming levels). There is also a lot of cotton in the air and I know it's been getting in the water. Could sun and cotton bring the FC down that fast? Now I'm concerned :( Advice??
Sunlight steals FC by percentage, not by a fixed parts per million. So the higher the FC, the more you lose to the sun. Is the water still sparkling? Toss the kids in, then!

Here's a graph I stole from this thread that shows the rate of FC loss. You'll note there isn't even a line for 20 FC, but it would no doubt be even steeper than the others. https://www.troublefreepool.com/~richardfalk/pool/ChlorineLoss.gif
 

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