TF 100 test kit help

aaronsappl

Member
Jun 18, 2010
17
MS
New pool built appx 1 month ago. I have read pool school. I have been running my Eco-Matic ESC 36 for 12 hrs a day on 100% and have avg. 1-2 FC. Water is clear. This SWG is supposed to be for 40,000 gallon pool. After reading on this forum, I ordered the TF-100 test kit. I am afraid my SWG is not putting out enough chlorine. After running it 36 hours on 100% this is my reading. FC-3 and CC 0.5. Also there is a big difference in my reading and the pool store. I know I have stabilizer in pool because i added it. Added more to get to 70-80 cya per pool school. I have done the test two times and both times 20 or less on cya. Pool store has CYA at 76. I know from reading the test is subjective. I went outside with back to sun and black dot never disappeared. I have enjoyed reading the forum and learning. I have added lo'n slo to drop PH. Thanks for any advice.

Pool store 7/17/10
TC- 1.2
TA- 73
PH- 7.9
CH- 208
CYA- 76
Borates- 29

TF-100 7/18/10
FC- 3
CC- 0.5
PH- 8.2
TA- 110
CA- 360
CYA- 20 or less
 

kenmccall

LifeTime Supporter
Mar 24, 2009
77
Macon Ga
Have you done an overnight test on the FC to see what the loss is? If it is more then 1PPM then you will need to shock the pool. I would bet this is your issue and this is why you are having to operate the SWG at 100% if your CYA is truly in the 70 range.
 

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
22,969
SouthWest Alabama
Welcome to TFP.

First thing is to believe your TF-100 results. How long ago did you add the CYA? if it's been more than a week and the TF-100 says you have no stabilizer and you're confident in your method then believe it.

The first thing I'd do is add enough stabilizer to get to 70ppm. You can use the Pool Calc to figure out how much that'd be.
 

kenmccall

LifeTime Supporter
Mar 24, 2009
77
Macon Ga
If you do need to shock the pool it will take a lot less chlorine to shock it at 20PPM CYA then 70PPM. I would shock it first if needed then bring the CYA up to 70PPM which is very important for your SWG system.
 

aaronsappl

Member
Jun 18, 2010
17
MS
Thanks, No I am not confident in my testing. Just have used the TF-100 two times. I will do a overnight FC loss test and will post results. I am pretty confident in all test except the cya. I dont want to add more stabilizer and then have to drain pool if I was wrong.
 

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
22,969
SouthWest Alabama
I completely understand how you feel. As long as you're mixing the R-0013 half and half with pool water and shaking it then setting it down for 30 seconds, then shaking it again, you're doing the test right. You can pour the test back and forth in the view tube several times to get a good read. You can trust the CYA test in the TF-100 a lot more than the pool store.
 

aaronsappl

Member
Jun 18, 2010
17
MS
I did not do the FC overnight loss last night because it rained hard. I have run my SWG on 100% for 36 hrs and this is the results. I will do the overnight loss tonight. I think my problem is that my CYA is low even though pool store says CYA is 76. I did the CYA 2 more times and same results is fill to the top and I can still see a light gray shade dot. I assume this means less than 20 CYA. My pool is in the sun from sunup till appx 5:30 in the evening. Water is clear. I think i need to trust the TF-100 test and buy some more stabilizer and add tomorrow.
07/20/10

Temp 86
FC-2
CC-0.5
TC-2.5
PH-7.8
TA-110
CH-320
CYA-<20
Borates-30
Salt- 3330
My Eco Matic SWG says a minimum of 3500ppm and the optimum salt levels should be 4500 to 5000ppm. Do you think I should add more salt. Everything I read on this site says I have enough salt. I wished now I would have bought a different SWG. Thanks for any advice.
 

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
22,969
SouthWest Alabama
You need to trust the TF-100 and yourself. Add enough CYA to get to 60 and give it a week and test again to see where you're at. If it's close you can just add enough to get to 70 and don't worry about testing it again.

Most US SWCG's require a salt level in the 3,000 to 4,000ppm range but there are some that require higher. You should maintain your salt level according to the mfg recommended.

How are you getting the 3330ppm salt reading?
 

aaronsappl

Member
Jun 18, 2010
17
MS
Bama Rambler said:
Does the Eco-matic have a readout?
Is it working?
If so what does it say?
No read out except for percentage. It has 2 indicator lights that change colors or blink. Both lights indicate every thing is ok with Eco-matic SWG.
 

aaronsappl

Member
Jun 18, 2010
17
MS
anonapersona said:
aaronsappl said:
I did the overnight loss test this am. No loss.
FC-2
CC-0.5
TC-2.5
SWG was off all that time?
SWG has been running from 6am to 6pm. I took that am FC loss at appx 7am. So SWG had been on for appx 1 hour. Sorry did not think of that.
 

Bama Rambler

Mod Squad
TFP Expert
LifeTime Supporter
Jun 22, 2009
22,969
SouthWest Alabama
If your SWCG is happy then I wouldn't worry about it too much. However given that the salt test strips have an accuracy of about 400ppm. Lets assume the reading you got was 400 too low and your reading is really 3730 then you'd be within the SWCG's window of acceptable. But if you wanted to be sure you could add 3 bags and then you'd be about 4400. At that point I'd check it again to be sure not to overshoot the max.

But all that isn't the big issue. Your CYA is right now.
 

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