Clear Blue Water but still new algae everyday

bjsbuds

LifeTime Supporter
Mar 16, 2012
129
Cincinnati, OH
Put three jugs of 10% bleach in last night when the FC was at 14. Need to keep adding Bleach and Stablizer.

Just took reading:
FC = 12
CC = 1
PH = 8.2
Acid Test = 3 drops
TA = 160
CH = 200
CYA = pretty close to zero

104398
 

bjsbuds

LifeTime Supporter
Mar 16, 2012
129
Cincinnati, OH
No algae present this morning.
FC - 17
pH - 8.0
TA - 150
CH - 225
CYA - 55
Salt - 1600

My real question is am I running the risk of not having this taken care of since I am not maintaining FC 30ppm?
 

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bjsbuds

LifeTime Supporter
Mar 16, 2012
129
Cincinnati, OH
Swell, more money down the drain. Just tested the pool, and FC is down to 7. Tested it twice. Pool looks great, no sign of algae, but I am sure I should not have lost 10 ppm of FC in 10 hours. I am going to get the FC up to 30ppm, I just hope I don't bleach out my new liner. If I am doing anything wrong I would really appreciate advice from the experts.
 

CarolineM

Silver Supporter
Jun 20, 2018
218
Annapolis, MD
Swell, more money down the drain. Just tested the pool, and FC is down to 7. Tested it twice. Pool looks great, no sign of algae, but I am sure I should not have lost 10 ppm of FC in 10 hours. I am going to get the FC up to 30ppm, I just hope I don't bleach out my new liner. If I am doing anything wrong I would really appreciate advice from the experts.
With your CYA at 55, it is 60 as we round up. Your shock level is 24 according to the chart.

 

CarolineM

Silver Supporter
Jun 20, 2018
218
Annapolis, MD
CarolineM, What does that mean?
If you look at the chart I provided the link to it shows if your CYA is 60 your SLAM level for chlorine would be 24 ppm not 30. No point in going higher than the recommended SLAM level, as you don't want to risk bleaching your liner.

CYA levels are measured in 10's, there is no 45, 55, 65 etc..so you round up. You stated yours was 55 so it is 60 and that is the number you use to get your SLAM level of 24 ppm
 

bjsbuds

LifeTime Supporter
Mar 16, 2012
129
Cincinnati, OH
Well, I am about to give up and call a professional pool service company. Added 8 gallons of bleach last night, and this morning it was over the top (40+ppm). I was sick thinking I surely over did it. When I got home from work I checked the chemicals again, and FC is down to 15ppm. What the heck. No trace of algae anywhere. Other levels:
FC - 15
CC - 1
PH - 7.6
TA - 170
CH - 200
Salt - 1,800
CYA - 50

I have now put in over 30 gallons of 10% bleach, and feel I am no closer to being finished.
 

CarolineM

Silver Supporter
Jun 20, 2018
218
Annapolis, MD
Do not add anymore stabilizer, the higher the CYA the more chlorine you will need to SLAM. Also your saltwater generator needs to be turned off during a slam. PH cannot be properly measured with chlorine levels over 10, so no need to test that right now. The only thing you need to test is your FC. When it drops below your target for SLAM add just enough to bring it back up to your slam target. Test and add as often as you can during the day and evening. Do not go above your target as it is only wasting chlorine.

After you test for FC put the number into the now column, then enter your target number in the target column that will show you how much chlorine to add to bring it to target for the SLAM.

You also need to brushing and vacuuming frequently. The more you do this the faster the SLAM will go. You also need to be checking your filter, it may need to be cleaned.
 

bjsbuds

LifeTime Supporter
Mar 16, 2012
129
Cincinnati, OH
Thank you for the responses. I checked the chemicals early this morning.
FC - 30
CYA - 40
Checked everything else, but no need to report since FC and CYA are what is important at this point.

Unfortunately, I work long hours during the week, so it is hard to check chemicals frequently. Won't be able to check again until very early morning in the dark.

I will target FC of 24. I do brush whenever I can. Also run Dolphin automatic cleaner, and bleach filters are each use.
 
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bjsbuds

LifeTime Supporter
Mar 16, 2012
129
Cincinnati, OH
Well I am sure all of you who read this thought, we if they can attend to their pool daily, nothing will get resolved. Yep, you are right. Haven't checked the pool for two days, and I just got home from work to see algae back in the bottom of the pool. Tested FC - 12 and CYA - 30 only. I am going to be able to babysit the pool for the next three days.

According to old pool math, it says I need two jugs of bleach and 6 lbs. or 1+ gallons of stabilizer. I think I read where you should not put bleach in the pool the same time as stabilizer. Not sure which is more critical, so I am going to start with bleach tonight. I am going to take the cartridge filters out tomorrow and clean them thoroughly. Plan to get in the pool and scrub the walls too.

Appreciate you sticking with me
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
11,594
Houston, Texas
You can add bleach and stabilizer at the same time, however when you are slamming you do not want to raise the CYA above 30. Leave it where it is for now.
 

bizurk1

Gold Supporter
May 2, 2016
30
Orlando/Florida
You can add bleach and stabilizer at the same time, however when you are slamming you do not want to raise the CYA above 30. Leave it where it is for now.
Wish I would have realizes this years ago. Always thought, because of 60*(not recommended) in CYA/FC chart. That CYA Had to be 70-80 for SWG pools.
 

jseyfert3

Well-known member
Oct 20, 2017
253
Janesville, WI
Thank you for the responses. I checked the chemicals early this morning.
FC - 30
CYA - 40
Checked everything else, but no need to report since FC and CYA are what is important at this point.

Unfortunately, I work long hours during the week, so it is hard to check chemicals frequently. Won't be able to check again until very early morning in the dark.

I will target FC of 24. I do brush whenever I can. Also run Dolphin automatic cleaner, and bleach filters are each use.
So, I read through this entire thing while bored at work (I'm here only in case something goes wrong at the moment) and I hope you don't mind me sharing some of my thoughts, to try and get this solved for you.

Firstly, I think you need to do a detailed read of the SLAMing article. There are a couple indications in my readthrough that seem to show you haven't fully read and/or understood the article. One such is that you have continued to test everything, despite many people telling you there is no need to. In fact, it's more than that there is no need, it's that the results may not be trustworthy, and as such, less that worthless. When the FC is above 10, the pH reading will be wrong. The chlorine oxidies the reagent and changes the color. The reagent used in the pH test neutralizes the FC in the test sample to avoid this unfortunate result but there is only enough to neutralize a FC up to 10. Therefore the test is invalid if the FC is measured at more than 10, and should not be done. At extremely high levels, other tests can start getting screwed up, as you discovered last year. In short, check/adjust the pH before beginning a SLAM, and do not test it (or anything except FC/CC) until the SLAM is done and the FC drops below 10.

Secondly, are you 100% certain you are following the directions correctly for FC readings? I noticed that last year, you kept posting results to 0.2 ppm accuracy (25 mL sample level) for a while. After several people said to use a 10 mL sample, it seemed to me that your FC readings jumped. I just want to be sure that this was a coincidence and not bad testing technique. Two scoops powder, then add reagent until clear, multiplying drops by 0.5 (10 drops = 5 ppm, 20 drops = 10 ppm). Be sure the bottom of the meniscus lines up with the 10 mL mark. If you have and use a SpeedStir (HIGHLY recommended!), be sure to measure the water before adding the magnet. Pro tip: I discovered that the normal saline syringes my nurse wife always is bringing home on accident are awesome for quickly getting an exact 10 mL sample. Fill, empty (to rinse), then fill, tip upside down to push bubbles to top, squeeze until rubber lines up with 10 mL mark, then squeeze into mixing tube on the SpeedStir. Something like this.

Well I am sure all of you who read this thought, we if they can attend to their pool daily, nothing will get resolved. Yep, you are right. Haven't checked the pool for two days, and I just got home from work to see algae back in the bottom of the pool. Tested FC - 12 and CYA - 30 only. I am going to be able to babysit the pool for the next three days.

According to old pool math, it says I need two jugs of bleach and 6 lbs. or 1+ gallons of stabilizer. I think I read where you should not put bleach in the pool the same time as stabilizer. Not sure which is more critical, so I am going to start with bleach tonight. I am going to take the cartridge filters out tomorrow and clean them thoroughly. Plan to get in the pool and scrub the walls too.

Appreciate you sticking with me
Yes, you need to check the pool more than once a day during a SLAM. Ideally, from what I read, multiple times a day, but a minimum of once at night and once in the morning. They need regular checks and additions even outside of SLAM, which ideally will prevent the pool from needing SLAM in the first place. ;)

The good news is, you got this last year, and you can get it again this year. The more often you check and adjust the FC, the faster you will finish your SLAM. And as you've seen, this forum is filled with knowledgeable, helpful people to assist you through the process.

Good luck, you got this!

Wish I would have realizes this years ago. Always thought, because of 60*(not recommended) in CYA/FC chart. That CYA Had to be 70-80 for SWG pools.
In order to start the SLAM
The article on SLAMing mentions this:
SLAMing an outdoor pool is most effective when CYA is around 30 to 40. Below 30 you lose too much chlorine to sunlight. As CYA goes up, SLAMing requires more and more chlorine, which starts to get impractical around 80 or 90. With CYA above 90 we recommend replacing water to get CYA down before you start the SLAM process.
 
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bjsbuds

LifeTime Supporter
Mar 16, 2012
129
Cincinnati, OH
Good morning everyone. Committed to the SLAM the next few days. Checked FC last night and it was 12. So I added two jugs on 10% bleach as the Pool Math suggested. I have been using the 10 mL sample level throughout this process because I am testing so much, and going through reagents quickly. I am fortunate to have the SpeedStir.

Tested around 7am this morning and FC = 25 (50 drops x .05), and just checked at 9:30am and FC dropped to 22 (44 drops x .05). So, I am going to add just enough bleach to keep it at the 24 level. I read the SLAM article again and the chart said for a SW pool and the lowest CYA was 60, even though mine is at 30, should be 24.
 

bizurk1

Gold Supporter
May 2, 2016
30
Orlando/Florida
If your CYA is at 30, should your Shock level only be 12?
That is what confused me about the , non SWG and SWG, CYA/FC chart. Don’t mean to confuse, but if CYA is 30 you may be wasting Chlorine.