I had my fiberglass pool refinished (Ecofinish) and can't get my chemicals balanced. The TA is stuck at 40 and the CH at 50. Ecofinish recommended Trichlor so I switched after the refill. Other than the low numbers the pool looked great for a month then started getting dark blotchy patches on the bottom. I added algeacide & conditioner which helped a little with the blotches but now the surface looks oily and I'm seeing oily gunk on the wall of the skimmer. What should I do now?
Low TA, CH
- Thread starter MSmiley
- Start date
- Jun 1, 2018
- 13,760
- Pool Size
- 26000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Trichlor is acidic & will tank ph & subsequently ta in short order.
It isn’t recommended for daily chlorination for that reason as well as the fact it adds cya. The free chlorine gets used up daily but the cya remains until water is replaced.
Conditioner is cya.
We recommend using liquid chlorine or a salt water chlorine generator for daily chlorination.
Here’s what every dissolved 8 oz trichlor puck does to your water.
As the cya level increases so does the necessary fc level required to keep your pool sanitary. FC/CYA Levels
Many Trichlor pucks & algaecides also contain copper- this can cause stains.
Can you post a picture of the stains?
Here’s some ways to help determine what type of stains you have
www.troublefreepool.com
Can you post your latest test results?
Fc
Cc
Ph
Ta
Ch
Cya
It isn’t recommended for daily chlorination for that reason as well as the fact it adds cya. The free chlorine gets used up daily but the cya remains until water is replaced.
Conditioner is cya.
We recommend using liquid chlorine or a salt water chlorine generator for daily chlorination.
Here’s what every dissolved 8 oz trichlor puck does to your water.
As the cya level increases so does the necessary fc level required to keep your pool sanitary. FC/CYA Levels
Many Trichlor pucks & algaecides also contain copper- this can cause stains.
Can you post a picture of the stains?
Here’s some ways to help determine what type of stains you have
Stains in Your Pool
The stained pool is beyond embarrassing. Our in-depth Guide to remove stains in your pool will help you to remove the stains and prevent them in the future.
www.troublefreepool.com
Fc
Cc
Ph
Ta
Ch
Cya
I've been using 1/2 oz. Tabs.
Fc - 2
Cc
Ph - 7.6
Ta - 40
Ch - 50
Cya - 20ish
My test kit doesn't include cya so I use a test strip. The pool is indoor so I'm not sure how no UV effects levels. Pretty much everything I read is for 10,000+ gal outdoor pools so I'm doing my best to learn. I've never had a problem keeping clear water, but the pool was old and badly stained when I bought the house - hence the refinish. I'm pretty discouraged that I'm getting stains/discoloration 2 months later. As for using chlorine, Ecofinish says it could cause bleaching.
I've attached a pic...it's hard to photograph because the water reflects the ceiling but you can see it's splotchy...a dark almost black. There's also a few brown areas popping up that may be from iron in the water pipes?
Fc - 2
Cc
Ph - 7.6
Ta - 40
Ch - 50
Cya - 20ish
My test kit doesn't include cya so I use a test strip. The pool is indoor so I'm not sure how no UV effects levels. Pretty much everything I read is for 10,000+ gal outdoor pools so I'm doing my best to learn. I've never had a problem keeping clear water, but the pool was old and badly stained when I bought the house - hence the refinish. I'm pretty discouraged that I'm getting stains/discoloration 2 months later. As for using chlorine, Ecofinish says it could cause bleaching.
I've attached a pic...it's hard to photograph because the water reflects the ceiling but you can see it's splotchy...a dark almost black. There's also a few brown areas popping up that may be from iron in the water pipes?
Attachments
- Jun 1, 2018
- 13,760
- Pool Size
- 26000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Even though the tabs are smaller they are still acidic & add cya.
Around 30ppm cya is all you need.
Liquid chlorine won’t cause problems if added properly & not allowed to sit on the surface- pour slowly infront of a running return (pencil sized stream) brush the area afterwards.
Try identifying the stains with the methods listed in the article .
What kit do you have?
Around 30ppm cya is all you need.
Liquid chlorine won’t cause problems if added properly & not allowed to sit on the surface- pour slowly infront of a running return (pencil sized stream) brush the area afterwards.
Try identifying the stains with the methods listed in the article .
What kit do you have?
- Jun 1, 2018
- 13,760
- Pool Size
- 26000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
- Mar 5, 2020
- 3,047
- Pool Size
- 66000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V35
Test kit - K-1004-1
Test strips - Pool & Spa 7 in 1 (for cya)
I'll test the stain today.
Added since refill (approx):
Trichlor 8 oz tabs - 2 (while waiting for .5 oz)
Trichlor .5 oz tabs - 20
McGrayel Easycare Beautec - 2 oz
Baking soda - 40 oz
Calcium hardness increaser - 28 oz
Algeacide - 5 oz
I've added the baking soda and cal hardness increaser about 6 oz at a time waiting overnight before adding the next. The numbers have not changed much at all. I brushed and vacuumed yesterday. I'll test again and post the results today.
Note: the finish installer told me to only add sanitizer and no brushing, so that's what I did for the first month. When I started getting the splotches I figured something was wrong so I checked the Ecofinish site and found their Chem level recommendations. They also say to add the McGrayel so that's what I did.
To maintain the same total alkalinity, you have to add 1.13 pounds of baking soda per pound of trichlor.
To maintain the same total alkalinity, you have to add 1.0 pounds of baking soda per (2) 3" tablets of trichlor (7 ounce weight per tab).
To maintain the same total alkalinity, you have to add 1.0 pounds of baking soda per (2) 3" tablets of trichlor (7 ounce weight per tab).
2C3Cl3N3O3 + 6H2O --> 2C3H3N3O3 + 6H+ + 3O2 +6Cl-
Trichlor + water --> cyanuric acid + hydrogen ions + Oxygen + chloride.
1 mole of trichlor creates 3 moles of hydrogen ions.
Trichlor + water --> cyanuric acid + hydrogen ions + Oxygen + chloride.
1 mole of trichlor creates 3 moles of hydrogen ions.
Cyanuric acid has a pKa of 6.88.
At pool pH (7.6), there is about 16% that is cyanuric acid and the rest is cyanurate.
100C3Cl3N3O3 --> 16C3H3N3O3 + 84C3H2N3O3- + 84H+
Adding CYA lowers the pH due to the released hydrogen ions, but the TA stays the same because there are the same number of cyanurate ions created as the number of hydrogen ions.
Each cyanurate ion counts towards the TA and each hydrogen ion counts against the TA for a net result of zero TA change.
When accounting for the TA change caused by trichlor, the effect of the CYA can be ignored by considering it as all cyanuric acid, which is what it will become as the sample is titrated down to a pH of 4.5.
www.wolframalpha.com
At pool pH (7.6), there is about 16% that is cyanuric acid and the rest is cyanurate.
100C3Cl3N3O3 --> 16C3H3N3O3 + 84C3H2N3O3- + 84H+
Adding CYA lowers the pH due to the released hydrogen ions, but the TA stays the same because there are the same number of cyanurate ions created as the number of hydrogen ions.
Each cyanurate ion counts towards the TA and each hydrogen ion counts against the TA for a net result of zero TA change.
When accounting for the TA change caused by trichlor, the effect of the CYA can be ignored by considering it as all cyanuric acid, which is what it will become as the sample is titrated down to a pH of 4.5.
y = 100-(100/(1+10^(6.88– x))), x from 5 to 9 - Wolfram|Alpha
Wolfram|Alpha brings expert-level knowledge and capabilities to the broadest possible range of people—spanning all professions and education levels.
www.wolframalpha.com
- Jun 1, 2018
- 13,760
- Pool Size
- 26000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Hayward Aqua Rite (T-15)
Your strips are wrong you’re bound to have more cya than that in the water
So 2ppm tc (this could be fc or cc who knows) is woefully low.
See—>> FC/CYA Levels
Here’s what your additions have put in the water.
PoolMath
You need switch to liquid chlorine asap & the ta will be fine. You can increase it to 50 with baking soda if you wish but it’s not completely necessary so long as you discontinue the trichlor.
You need the fas/dpd kit (k1515) to accurately test fc (good stuff) & cc (bad stuff) independently vs only testing TC & to be able to test over 5ppm.
This especially important in an indoor pool where cc’s tend to build up.
You also need the cya test kit.
These are both available on tftestkits.net
& amazon
So 2ppm tc (this could be fc or cc who knows) is woefully low.
See—>> FC/CYA Levels
Here’s what your additions have put in the water.
PoolMath
You need switch to liquid chlorine asap & the ta will be fine. You can increase it to 50 with baking soda if you wish but it’s not completely necessary so long as you discontinue the trichlor.
You need the fas/dpd kit (k1515) to accurately test fc (good stuff) & cc (bad stuff) independently vs only testing TC & to be able to test over 5ppm.
This especially important in an indoor pool where cc’s tend to build up.
You also need the cya test kit.
These are both available on tftestkits.net
& amazon
The abundance of information, sometimes conflicting is very overwhelming. I consider myself fairly intelligent but I don't have a degree in chemistry so doing complex calculations is not going to work for me. From what I've read, I believe my levels should be/is today (via kit except CYA & CH)
FC 1-3 / 5
TC 1-3 / 2.5
Ph 7.4 / 7.8
TA 80-120 / 95
CH 180-220 /
CYA - 50 / ? The color I get on the test strip. is lighter than 0
I will switch to liquid chlorine (it's OK to do that after using trichlor?) and buy the suggested tests. Could someone please confirm I have the correct target levels for an indoor pool with ecoFINISH?
According to the old pool Math page I should now add 37 oz hardness increaser. Do I add this all at once or over several days?
Thanks for your help!
FC 1-3 / 5
TC 1-3 / 2.5
Ph 7.4 / 7.8
TA 80-120 / 95
CH 180-220 /
CYA - 50 / ? The color I get on the test strip. is lighter than 0
I will switch to liquid chlorine (it's OK to do that after using trichlor?) and buy the suggested tests. Could someone please confirm I have the correct target levels for an indoor pool with ecoFINISH?
According to the old pool Math page I should now add 37 oz hardness increaser. Do I add this all at once or over several days?
Thanks for your help!
What Are My Ideal Pool Levels?
Use our tool to find ideal chemical levels for any swimming pool. Check TFP recommended levels on pH, free chlorine, cyanuric acid, and more.
www.troublefreepool.com
Further Reading
www.troublefreepool.com
- Jun 22, 2014
- 47,847
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
@MSmiley, this may seem overwhelming, but I can assure you we can keep it simple. Let me highlight some basics to help:
1 - With an indoor pool, you only need about 20-30 ppm of CYA. Then maintain the corresponding FC level to match that CYA as noted on the FC/CYA Levels. That's all you need to worry about for the algae prevention/sanitation portion of your water.
2 - To keep the water comfortable to the skin & eyes, prevent scale and reduce the likelihood of staining, we balance the TA, pH, and CH. The CH technically isn't needed since our FG shells do not contain plaster, but the CH can help to buffer the effects of staining. TFP recommends a CH of 200 only because we don't know if some FG owners have a waterline tile (plaster) or heater requirements. IMO, if none of those issues apply, a CH anywhere between 100 - 300 is fine. PH & TA will always be your most important and easily adjustable items in this area. PH is good anywhere between 7.2-7.8. For most of us, PH tends to drift up to 7.8 or higher, so we have to use muriatic acid to lower it a bit. If the TA is over 80, it can enhance the PH's ability to climb faster. If your TA is anywhere between 50-80 it's fine. "Generic" industry TA levels say 80-120, but that's because they expect the owner to use acidic tablets. TFP does not.
Once you receive a proper test kit, you will have 100% visibility of the water chemistry. Not hard at all. We'll be here to help coach you along the way.
As far as those darker blotches are concerned, I would be suspicious of the application versus anything chemically you have done to this point. Not sure if I missed it above, but have you reached out to the contractor who did the new finish? Since you have been following their recommendations (and Ecofinish) to this point, they should be taking good care of you for the first season.
Let us know if you have any other questions. Stay cool!
1 - With an indoor pool, you only need about 20-30 ppm of CYA. Then maintain the corresponding FC level to match that CYA as noted on the FC/CYA Levels. That's all you need to worry about for the algae prevention/sanitation portion of your water.
2 - To keep the water comfortable to the skin & eyes, prevent scale and reduce the likelihood of staining, we balance the TA, pH, and CH. The CH technically isn't needed since our FG shells do not contain plaster, but the CH can help to buffer the effects of staining. TFP recommends a CH of 200 only because we don't know if some FG owners have a waterline tile (plaster) or heater requirements. IMO, if none of those issues apply, a CH anywhere between 100 - 300 is fine. PH & TA will always be your most important and easily adjustable items in this area. PH is good anywhere between 7.2-7.8. For most of us, PH tends to drift up to 7.8 or higher, so we have to use muriatic acid to lower it a bit. If the TA is over 80, it can enhance the PH's ability to climb faster. If your TA is anywhere between 50-80 it's fine. "Generic" industry TA levels say 80-120, but that's because they expect the owner to use acidic tablets. TFP does not.
Once you receive a proper test kit, you will have 100% visibility of the water chemistry. Not hard at all. We'll be here to help coach you along the way.
As far as those darker blotches are concerned, I would be suspicious of the application versus anything chemically you have done to this point. Not sure if I missed it above, but have you reached out to the contractor who did the new finish? Since you have been following their recommendations (and Ecofinish) to this point, they should be taking good care of you for the first season.
Let us know if you have any other questions. Stay cool!
Thank you, that helps a lot. I did reach out to the Contractor and he said he could take a look next season if I wasn't happy with the finish (I live a few hours away). I also asked about a problem with air in my suction side - after the refinish - but he never replied. I have read TFP articles and tried all the suggestions to find the leak, other than digging up pipes, and can't find it.
I'll read or re-read the suggested articles and maybe it will all make sense this time...and I'll make a donation.
Based on what I've added do you know what could be causing the oily film on the pool surface and gunk in my skimmer and how to fix? I'm guessing it's the algeacide. Sorry if I'm being a pest but I'm afraid to add anything now.
I'll read or re-read the suggested articles and maybe it will all make sense this time...and I'll make a donation.
Based on what I've added do you know what could be causing the oily film on the pool surface and gunk in my skimmer and how to fix? I'm guessing it's the algeacide. Sorry if I'm being a pest but I'm afraid to add anything now.
- Jun 22, 2014
- 47,847
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Between the Beautec and algaecide I'm not seeing anything that would directly cause an oily film. Our pool water tends to pick up things from swimmers and the local environment. Something to watch after you are able to test the water yourself. To clean this skimmer you can use several things like a scrubby pad with a little bleach, Magic Eraser, etc.
For the suspected suction leak, those only started after the new gelcoat? If so, I would look carefully around the skimmer, weir for, etc. You might post pics of your equipment pad too so we can see all the lines, valves, etc. Maybe we'll see something to help on that issue.
For the suspected suction leak, those only started after the new gelcoat? If so, I would look carefully around the skimmer, weir for, etc. You might post pics of your equipment pad too so we can see all the lines, valves, etc. Maybe we'll see something to help on that issue.