I’ve been relying on Pinch a Penny to test and recommend chemicals and my algae is getting out of control. I’ve gone to “pool school” lol and just ordered a test kit. I was using the calculator and it shows that with my CYA at 60, the FC for SLAM should be at 24. This sounds insanely high, and I don’t want to damage anything. I’ve been taking care of my pool 6 months now and have kept everything in the recommended range from Pinch a Penny, but now understand the balance between FC and CYA after spending some time on the site. Is it 100% safe to bring FC up to 24? Is there anything I can do in the meantime? I only have a regular test kit now and it only goes up to 5. Not planning on swimming in it, just want to get it somewhat under control in the meantime.
SLAM recommendations
- Thread starter SmotheredHope
- Start date
- Jul 21, 2013
- 65,157
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Welcome to TFP.
Yes.
You need to read CYA Chlorine Relationship - Further Reading and learn how CYA divides the FC between active chlorine and reserve chlorine.
Download PoolMath
How many gallons in your pool?
When you get your test kit post your test results here.
www.troublefreepool.com
Yes.
You need to read CYA Chlorine Relationship - Further Reading and learn how CYA divides the FC between active chlorine and reserve chlorine.
Add 5 ppm of FC per day of liquid chlorine until you get your test kit.
Download PoolMath
How many gallons in your pool?
When you get your test kit post your test results here.
Algae Archives
www.troublefreepool.com
Hi, thank you for your reply. Pool is 17k gallons. I downloaded the pool math app, but don’t see how to calculate how much chlorine to add to figure out what 5ppm would be.Welcome to TFP.
Yes.
You need to read CYA Chlorine Relationship - Further Reading and learn how CYA divides the FC between active chlorine and reserve chlorine.
Add 5 ppm of FC per day of liquid chlorine until you get your test kit.
Download PoolMath
How many gallons in your pool?
When you get your test kit post your test results here.
Algae Archives
- Jul 21, 2013
- 65,157
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Hello,
Just got my test kit and I’ma bit worried. I’ve been adding the chlorine and now my FC is at 61. Here are the rest of the results:
CC 0
CYA 70
Alkalinity 110
PH above 8.2
Calcium 300
Salt 2800
- May 3, 2014
- 62,687
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40
I used the instructions in the book.
Rinse chlorine only cylinder
Filled to 10 ml
Used small spoon and scooped R-0870 (level scoop) and swirled. It turned pink.
While swirling, added R-0871 until clear
Multiplied by .5
Added 5 drops off-0003 and swirled. It stayed clear.
And when I did the block test it turned orange. Level was slightly low, so just added about 3” of water to try and dilute. Let me know if I should drain a bit
- Jul 21, 2013
- 65,157
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
How does your pool water look?
The liquid Chlorine you added was maybe 30 ppm of FC.
Your FC test took 120 drops?
Are you using a SpeedStir?
Do not adjust your pH. With a FC over 10 the pH test is invalid.
The liquid Chlorine you added was maybe 30 ppm of FC.
Your FC test took 120 drops?
Are you using a SpeedStir?
Do not adjust your pH. With a FC over 10 the pH test is invalid.
It's been about 6 days since the advice given. So if you've been adding 1 gal per day, it means that currently your pool is not using up a lot chlorine. So it has been building up.
The SLAM levels you see here or in Pool Math are safe, even to swim in. You are testing salt levels too. Do you have a Salt Generator? If so, that has also been adding Cl, making your levels go higher faster. Turn it off if doing the SLAM.
For SLAM, you should initially be testing every few hours, and adding however much Cl is needed to get your level back to the goal. Pool Math should tell you directly, or you can use the section in it called "Effects of Adding" to see how much does what. As SLAM goes on, you'll find you can test some less, and not have to add as much.
Even during normal times - test first, before adding, to verify. Give it all time to mix - 1/2 to 1 hr, before testing again if you feel it is needed. You may have picked a sample where the Cl was not completely mixed with the water after adding, so would test high. Try again after a bit more mixing time, to verify the high reading.
For now, how's the algae? Have you brushed and it is gone, with nothing dirt like settling in the pool? Is your water crystal clear? If not there yet, stop adding Cl for a bit - but test to watch it drop until it gets to SLAM level. The time it takes depends completely on how high it really is and the algae load, so could be hours or a couple of days. Don't swim until it gets to SLAM level. Then go back to adding just what is needed to keep it at SLAM level. When no "dirt" and water is clear, read how to do the "OCLT" (Overnight Chlorine Loss Test) to see if hidden algae in the pool is still consuming Cl. If you pass that test, you are done with the SLAM, and can let it drift down to the target levels. Always keep it at the target level - minimum is just that, never let it get that low.
The SLAM levels you see here or in Pool Math are safe, even to swim in. You are testing salt levels too. Do you have a Salt Generator? If so, that has also been adding Cl, making your levels go higher faster. Turn it off if doing the SLAM.
For SLAM, you should initially be testing every few hours, and adding however much Cl is needed to get your level back to the goal. Pool Math should tell you directly, or you can use the section in it called "Effects of Adding" to see how much does what. As SLAM goes on, you'll find you can test some less, and not have to add as much.
Even during normal times - test first, before adding, to verify. Give it all time to mix - 1/2 to 1 hr, before testing again if you feel it is needed. You may have picked a sample where the Cl was not completely mixed with the water after adding, so would test high. Try again after a bit more mixing time, to verify the high reading.
For now, how's the algae? Have you brushed and it is gone, with nothing dirt like settling in the pool? Is your water crystal clear? If not there yet, stop adding Cl for a bit - but test to watch it drop until it gets to SLAM level. The time it takes depends completely on how high it really is and the algae load, so could be hours or a couple of days. Don't swim until it gets to SLAM level. Then go back to adding just what is needed to keep it at SLAM level. When no "dirt" and water is clear, read how to do the "OCLT" (Overnight Chlorine Loss Test) to see if hidden algae in the pool is still consuming Cl. If you pass that test, you are done with the SLAM, and can let it drift down to the target levels. Always keep it at the target level - minimum is just that, never let it get that low.
Water looks pretty good. Yes to all of your questions. I think it got so high because I also had the SWG on. Yes to all of your questions. I turned the SWG off. Should I drain water, and fill to get the chlorine down? I’m worried about damaging the equipment
- Jul 21, 2013
- 65,157
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
More like 4 to 5 days of liquid chlorine added.
With CYA of 70 SLAM FC is 28.
No reason to talk about adding more chlorine right now.
Last edited:
Here's an old thread about "too high" Cl. Can really high chlorine levels damage pool equipment?
You will be fine. Just don't make it standard practice.
BTW - we forgot to assign some homework -
1. On this page, got to "Settings", then on that one "Signature". List out as much as you can:
Total gallons of the pool, type of construction (vinyl, plaster, etc), Make and models of all your equipment (Filter, Pump, SWCG, heater, etc.) any add-ons (spas, waterfalls), which test kit. If you don't know now, you can go back and edit/add later. See the responses from others for examples. Avoids us asking, or making bad assumptions, later.
2. In Pool Math, way down under Settings, you can link your Pool Math entries to your user name here. If you save results, and even better log what you put in, when, we can see it here. And you don't have to retype. Click on my user name to go to "Pool Math logs" for an example . (Winter here, so not much recent!).
You will be fine. Just don't make it standard practice.
BTW - we forgot to assign some homework -
1. On this page, got to "Settings", then on that one "Signature". List out as much as you can:
Total gallons of the pool, type of construction (vinyl, plaster, etc), Make and models of all your equipment (Filter, Pump, SWCG, heater, etc.) any add-ons (spas, waterfalls), which test kit. If you don't know now, you can go back and edit/add later. See the responses from others for examples. Avoids us asking, or making bad assumptions, later.
2. In Pool Math, way down under Settings, you can link your Pool Math entries to your user name here. If you save results, and even better log what you put in, when, we can see it here. And you don't have to retype. Click on my user name to go to "Pool Math logs" for an example . (Winter here, so not much recent!).