We had an issue with high CC (above 2), so we began the SLAM process Monday morning using FAS-DPD test. We have gotten the CC under control, but our FC has only gotten above 1 on one test. We are adding 60-70 ounces of 12.5% liquid chlorine every few hours based on Pool Math calculations and seeing no increase in our FC. Test results from this morning below, is there something else we need to be looking at to solve our chlorine problem?
- Jul 21, 2013
- 65,157
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Test your FC 30 minutes after adding it.
Show us a complete log with dates and times of results of FAS/DPD test, amount of chlorine added, and FAS/DPD test 30 minutes after adding chlorine.
PoolMath will maintain the log for you and you can enable log sharing so we can view it.
Show us a complete log with dates and times of results of FAS/DPD test, amount of chlorine added, and FAS/DPD test 30 minutes after adding chlorine.
PoolMath will maintain the log for you and you can enable log sharing so we can view it.
- Jul 21, 2013
- 65,157
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
70 oz of 12.5% liquid chlorine should give you 4.6ppm
What is the date code on the bottle?
Show us the labels on the liquid chlorine you are using.
What is the date code on the bottle?
Show us the labels on the liquid chlorine you are using.
- Jul 21, 2013
- 65,157
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
That is fresh stuff.
So add more until you get to your FC target when testing 30 minutes after you add the chlorine.
So add more until you get to your FC target when testing 30 minutes after you add the chlorine.
Hoster
Silver Supporter
Some lessons learned over the years / this year (although YMMV):
1. as for the initial dose of chlorine, I found "more the better" - e.g., overdose chlorine from the beginning seemed to work better for me then adding "some" multiple times throughout the day (not giving algae any chance to come back)
2. and I "dump" my liquid chlorine at night
3. filter media - I think you have sand but our DE filter cartridges were baked with green-ish clumps - cleaned out and worked better
4. pool store's 5 gallon jug seemed to work better than Walmart's (not old) gallon bottles (however, Walmart's Pool Essential's bottles are 10% but yours is 12.5% just like pool store's)
Hope this helps!
1. as for the initial dose of chlorine, I found "more the better" - e.g., overdose chlorine from the beginning seemed to work better for me then adding "some" multiple times throughout the day (not giving algae any chance to come back)
2. and I "dump" my liquid chlorine at night
3. filter media - I think you have sand but our DE filter cartridges were baked with green-ish clumps - cleaned out and worked better
4. pool store's 5 gallon jug seemed to work better than Walmart's (not old) gallon bottles (however, Walmart's Pool Essential's bottles are 10% but yours is 12.5% just like pool store's)
Hope this helps!
Finally got FC up to 5 by checking and adding every 30 minutes, but not until the pool was completely in the shade, so perhaps a sign that our CYA is too low? That test plays tricks with my mind so I could have my number wrong. We started the season with a ridiculously high number over 170 (according to pool store test), drained and filled to get it down, perhaps drained too much?
- Jun 24, 2021
- 15,961
- Pool Size
- 29000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-60 Plus
why was your CYA so high to start? were you using pool store products?
i'm seeing that one's process to open and maintain a pool varies a lot depending on your area of the country. Here we have basically straight rainwater when we open so it has zero CYA, near zero CH, very low pH. I just dump in chlorine, wait till the worst of any back flushing is done, bring up cya to 30-40, and away we go.
this year it took a lot more chlorine than usual to get started. in hindsight, reading this forum, it's because we used a dozen chlorine bottles to tie down our pool cover for the winter. I think even our limited winter daylight ate away at the chlorine and we were just dumping in expensive water. lesson learned. our fresh bottles worked great.
i'm seeing that one's process to open and maintain a pool varies a lot depending on your area of the country. Here we have basically straight rainwater when we open so it has zero CYA, near zero CH, very low pH. I just dump in chlorine, wait till the worst of any back flushing is done, bring up cya to 30-40, and away we go.
this year it took a lot more chlorine than usual to get started. in hindsight, reading this forum, it's because we used a dozen chlorine bottles to tie down our pool cover for the winter. I think even our limited winter daylight ate away at the chlorine and we were just dumping in expensive water. lesson learned. our fresh bottles worked great.
Trichlor tabs and dichlor shock to try and eliminate algae last summer and mold when opening this summer having no idea that it would raise CYA so high.
- Jul 21, 2013
- 65,157
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
First post says...
Your first post listed CYA 40 which is fine for the SLAM Process.
SLAM FC for CYA 40 is FC of 16.
Okay, wow, that is much higher than we have been aiming for. I had no idea that tiny little circle on the app turned on the target for SLAM, I thought the number next to the word SLAM was the target.
- Jul 21, 2013
- 65,157
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Okay, so add whatever amount of chlorine is needed to get your FC up to 16 and let's take a checkpoint on where you are.
Just to check that on the FAS/DPD FC test you are using a 10ML sample where each drop is 0.5 ppm. FC of 16 would be 32 drops to flip from red to clear.
Just to check that on the FAS/DPD FC test you are using a 10ML sample where each drop is 0.5 ppm. FC of 16 would be 32 drops to flip from red to clear.
I added 256 ounces last night to get up to 16 and first test this morning was at 0.5 for both FC and CC. Water is crystal clear and has been since we changed the sand in our filter a couple of weeks ago. Not sure what could be causing that much chlorine to burn up over night.
- Jun 24, 2021
- 15,961
- Pool Size
- 29000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-60 Plus
PH is 7.0, was 7.2 when we started and I have the Borax to raise it just didn’t want to mess with the SLAM process by adding it before getting the chlorine fixed. CYA is maybe 50, I struggle to get the same number multiple times in a row on that test. We do have an automatic chlorinator for pucks, but shut that off when we started the SLAM process, not sure if residual CYA is still coming off of those.
- Jun 24, 2021
- 15,961
- Pool Size
- 29000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-60 Plus
When was the last time you tested CYA?
Are you using pool math? If so, go to the gear in the upper right, then scroll to the bottom and enable sharing with TFP. Ensure your login is the same as the forum. Like to see your logs.
Are you using pool math? If so, go to the gear in the upper right, then scroll to the bottom and enable sharing with TFP. Ensure your login is the same as the forum. Like to see your logs.
Sunday night we got 40, but we also did that test without standing with our back to the sun and holding waist high, we are brand new to testing our water ourselves. PoolMath Logs
- Jun 24, 2021
- 15,961
- Pool Size
- 29000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-60 Plus
Do the test again now if you can. Follow the instructions and report what you get.
www.troublefreepool.com
CYA - Cyanuric Acid Test
Cyanuric acid (CYA) is the chemical name for the product commonly called “pool water stabilizer” … Read more…
www.troublefreepool.com