Sorry, yes, I bought SunCoast liquid chlorine with 10.5% sodium hypochlorite. I have 3 jugs of the 2.5 gallon.
Thanks
1st time user of TF-100 kit and Pool Math
- Thread starter kingadriann
- Start date
Thanks
- Jun 8, 2019
- 4,576
- Pool Size
- 20000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
You will need to keep your FC at a very high level due to the high CYA. Above 10 FC, the pH test won’t work, too.
I would exchange out 50% of the water. Be careful - if you aren’t sure if it’s safe to drain, do a no-drain water exchange:
www.troublefreepool.com
While 30 is good for CYA, you may want to start being more around 50-60. If you need to SLAM to get rid of the algae it will require a higher FC level than 30 does, but it will protect your chlorine more from the sun, and I have to imagine in Texas it’s pretty brutal.
I would exchange out 50% of the water. Be careful - if you aren’t sure if it’s safe to drain, do a no-drain water exchange:
Draining - Further Reading
www.troublefreepool.com
While 30 is good for CYA, you may want to start being more around 50-60. If you need to SLAM to get rid of the algae it will require a higher FC level than 30 does, but it will protect your chlorine more from the sun, and I have to imagine in Texas it’s pretty brutal.
PoolMath tells me to add 5 gallons of 10% to get to 26 ppm. in your 20k pool. 26 ppm is somewhat arbitrary but it gives you the FC you need to kill the rest of the algae and 2 jugs conveniently gets you there.
So, put in the FC and right away brush that algae off the pool floor (sides, too?) the next AM, vacuum if any algae is visible on the pool floor. After that brush again to get it up into the pool water where chlorine will kill it.
Next, let your FC drift down to 10 ppm and post a full set of test results and tell us how your water looks.
Drain/refill is a good idea but let's get your pool clean first.
I poured 5 gallons at 9 p.m. last night, all around perimeter of the pool, brushed all the algae off with pump running. It's been 12 hours, should I test the water now or wait till 12 more hours later? Meanwhile I will keep brushing. There is the ledge area under the waterfall that is hard to brush so I might have to jump in and brush it off. Thanks.
- Jun 8, 2019
- 4,576
- Pool Size
- 20000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
- Jun 8, 2019
- 4,576
- Pool Size
- 20000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Don’t worry about the comparator test. The drop test for chlorine is fine. Also don’t worry about the pH test with FC over 10.
The thread title states you have a TF-100 test kit which contains a FAS-DPD drop test that can measure FC above 5 ppm. It also tests CC.
The test you pictured is an OTO test which only goes up to 5 and additionally only measures TC (total chlorine, which is the sum of free chlorine FC and combined chlorine CC). The TC value is not really useful because you have no idea how much is FC (good) versus CC (bad).
If you have the FAS-DPD test, use that to determine your true FC and CC.
Also, the pH measurement is invalid when FC is 10 or more. It reads artificially high.
The test you pictured is an OTO test which only goes up to 5 and additionally only measures TC (total chlorine, which is the sum of free chlorine FC and combined chlorine CC). The TC value is not really useful because you have no idea how much is FC (good) versus CC (bad).
If you have the FAS-DPD test, use that to determine your true FC and CC.
Also, the pH measurement is invalid when FC is 10 or more. It reads artificially high.
Ok so should I add a little bit more chlorine now or tonight? I cannot get the recommendation from Pool Math because I don’t know what to enter for PH.
Forget about pH during a SLAM. You can worry about that once your FC drops back below 10.
I just reread and noticed you said your FC is 19, so I guess you are using the FAS. To perform a proper SLAM, FC must be maintained at 40% of CYA. So for you, that would be 48. That's a lot of chlorine, which is why duraleigh advised you to drain and refill to drop your CYA to a more manageable level. 40 would be ideal, but only you can decide how much you want to spend refilling your pool versus buying chlorine.
I just reread and noticed you said your FC is 19, so I guess you are using the FAS. To perform a proper SLAM, FC must be maintained at 40% of CYA. So for you, that would be 48. That's a lot of chlorine, which is why duraleigh advised you to drain and refill to drop your CYA to a more manageable level. 40 would be ideal, but only you can decide how much you want to spend refilling your pool versus buying chlorine.
Last edited:
I have a party this Friday and the kids want to swim. If I don’t want to drain the pool this week, so that means I have to keep putting in liquid free chlorine till it reaches 40, does that sound right? Please advise, thanks!
- Jun 8, 2019
- 4,576
- Pool Size
- 20000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
It depends on what your goal is.
If your goal is to just stop any algae you have from getting worse, keeping FC up above 10 should suffice. If you want to actually eradicate the algae completely, you’ll need to get it up to 48 and hold it there as much as you can, which is somewhat impractical. Replacing water to get your CYA lower will help you with a lower FC target.
Ok for now I will keep adding liquid chlorine to kill algae. After Friday, I will drain pool to lower cya and when it is low enough, I will add more liquid chlorine to shock pool. Thanks!
- Jun 8, 2019
- 4,576
- Pool Size
- 20000
- Surface
- Vinyl
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
This doesn't really answer your question (I'm not familiar with what looks to be a cartridge or DE filter), but if you're going to drain some down it's much safer to rent or buy a smaller submersible pump and use that to pump out the water. If your pump runs dry it can damage the pool pump.
What sort of pool surface do you have? Vinyl, plaster?
What sort of pool surface do you have? Vinyl, plaster?
It does not appear you have a vac to waste option. You would need a 3 way valve with a leg to waste before the a cartridge filter like seen here.
You do have a spigot above the pump and a garden hose which will allow you to do small drains, just slowly.
You do have a spigot above the pump and a garden hose which will allow you to do small drains, just slowly.
Ok pool water looks much more clear and I did the test
FC - 33 (66 x 0.5)
CC - 0
CYA -100
TA - I stopped at 35 drops of R-009 which is at least 350
And Some green spots on the very bottom of the pool, no matter how much I brush, is not going away. I also see rust spots, any recommendations
How to remove these stains?
Pictures attached, thank you
FC - 33 (66 x 0.5)
CC - 0
CYA -100
TA - I stopped at 35 drops of R-009 which is at least 350
And Some green spots on the very bottom of the pool, no matter how much I brush, is not going away. I also see rust spots, any recommendations
How to remove these stains?
Pictures attached, thank you
Attachments
Ah that explains why. My husband put the spigot there so we can do that small drains - thanks for the explanation.
I see lots of recommendations to use crushed ascorbic acid on the rust stains. Any thoughts?Ok pool water looks much more clear and I did the test
FC - 33 (66 x 0.5)
CC - 0
CYA -100
TA - I stopped at 35 drops of R-009 which is at least 350
And Some green spots on the very bottom of the pool, no matter how much I brush, is not going away. I also see rust spots, any recommendations
How to remove these stains?
Pictures attached, thank you
- May 3, 2014
- 58,567
- Pool Size
- 6000
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-40