First test with TF100 kit

[Propbndr]

My first test with my new TF100 test kit:

FC 6.5
CC .5
PH 7.5
TA 120
CH 175
CYA 90-100 (repeated three times, hence the range)
Salt 4600
Temp 62 (burr)

FC high because I am dialing in my new SWG. Was set at 75%, running 12 hours / day. Dialed it down to 50%.

CYA high from using those stupid pucks, argh.

Don't know why salt is so high. I tested prior to buying the salt and brand new test strips showed no measurable salt in the pool. I used the Pool Math calculator and added 520 pounds of salt which should have given me a 3600 ppm level, my CircuPool SWG calls for 3500 ppm. A week ago, my brand new SWG readout started at 3500 but was reading 3900 yesterday, I don't know why the descrepancy between it and my tests and why the salinity reading is increasing when my test strips showed it to be steady.

Any ideas on the why salt level is nowhere close to the calculation, the descrepancy between SWG reading and tests, and the SWG reading increasing?

In any case I see a 22% water replacement in my future to knock the cya and salt levels down. Gotta do it in stages though because I am on a well and a 3700 gallon hit on it could cause me problems.

 

[BoDarville]

First of all, congrats on getting one of the recommended test kits and for posting a full set of #'s

At your current CYA level, your FC of 6.5 ppm is actually in-line. I would maintain it at that level until you get the CYA down into the 70-80 ppm range. See [FC/CYA][/FC/CYA] for more info (refer to the SWG chart on that page).

I'm not sure why the salt level is fluctuating. However, since it appears that you were using pucks for a chlorine source prior to the SWG, I would be very suspect of a test reading of zero before adding the salt. All forms of chlorine (pucks, liquid bleach, powders) will add some salt to the pool. I have a manually-chlorinated pool that I maintain with liquid bleach and my salt reading was 1,260 ppm when I tested for salt last week. I use the Aqua Check strips and they have been pretty reliable. However, if I had a salt pool, I would use the Taylor K-1766 salt test (http://tftestkits.net/K-1766-Taylor-Salt-Test-p31.html). It involves a bit more effort than the strips but, in return, you are getting a higher precision level.

 

[Propbndr]

For my initial salt test, I used brand new Clorox brand salt test strips. Visually, they are identical to the Aqua Check brand. The initial test level never got to the lowest measurement line on the strip (without looking at them, I think that minimum is 100 ppm). I just purchased, and used the Taylor K-1766 salt test kit. It's result was within 50 or so ppm with the strips which I ran at the same time.

I am wondering if there is some internal calibration adjustment on my SWG for the various read outs. My old brain would hate to have to remember to add 700 ppm to the displayed reading. I will have to figureout what other piece of useless life data to delete to make room.

 

[pooldv]

So, are you getting a high salt error? It should give you the error above 4000 ppm and will not make chlorine when in high salt condition. If you aren't getting the error then there isn't an issue.

The CYA goal for saltwater pools is 60-80ppm. I don't know that you necessarily need to drain to take it from 90ish to 80ish. Rain should dilute it soon enough.

 

[pooldv]

There is a possibility that your CYA could be higher than 100. 100 is the upper limit of the test and often a result of 100 can mean a higher reading.

Try the diluted CYA test to verify that cya is truly at 90-100.

Add pool water to bottom of sticker.
Add tap water to top of sticker.
Shake.
Pour out half so mixture is to bottom of sticker.
Add reagent to top of sticker.
Shake.
Test outside with back to sun and tube at waist level.
Pour back and forth a few times to see if you get the same result.
Double the result

 

[pooldv]

A couple more points on adding salt to your pool in the future. Don't add it all at once, with cya and salt it is much better to sneak up on those levels. Salt needs to circulate for 24 hours to fully dissolve before testing. CYA needs to dissolve for a week before testing and adding more.

 

[JamesW]

There was definitely some salt in the pool to begin with. There was probably at least 300 ppm. Salt tests are not particularly accurate or precise. Salt test error can be plus or minus 400 ppm. Also, some salt tests are chloride specific and some are based on conductivity. Those different types of tests won't always agree exactly.

The K-1766 salt test kit is a good thing to have with a SWG

 

[Propbndr]

First thing, thank you for all of your comments.

So, are you getting a high salt error?

I am not getting a high salt error. My SWG panel reading varies between 3800 and 3900 ppm. It is generating normally.

There is a possibility that your CYA could be higher than 100. 100 is the upper limit of the test and often a result of 100 can mean a higher reading.

Try the diluted CYA test to verify that cya is truly at 90-100.

I will try that test later today. Thank you for the instructions.

There was definitely some salt in the pool to begin with. There was probably at least 300 ppm. Salt tests are not particularly accurate or precise. Salt test error can be plus or minus 400 ppm. Also, some salt tests are chloride specific and some are based on conductivity. Those different types of tests won't always agree exactly.

The K-1766 salt test kit is a good thing to have with a SWG

I wish I knew about the accuracy of the various salt tests before I started adding salt. I would have approached the startup process more cautiously. I did buy the K-1766 kit along with my TF100 kit. It gave me a reading of 4600 ppm. I ran a comparison test, using the same sample, with my strips and got a 4550 ppm level. When I had 2 out of 3 indicators telling me that I had a high salt level, I assumed the third was in error.

A couple more points on adding salt to your pool in the future. Don't add it all at once, with cya and salt it is much better to sneak up on those levels. Salt needs to circulate for 24 hours to fully dissolve before testing. CYA needs to dissolve for a week before testing and adding more.

Hind sight being 20/20, I am kicking my self for not holding back on 2 or 3 bags of salt and titrating up to the correct level. The CYA was already in the water but, is much higher than I was expecting.

I drained about 10% of my pool and am in the process of refilling it. I hope the levels are closer to those suggested. If they are they are not close, between rainfall and backwash refills, I plan on letting nature take its course.

 

[pooldv]

Alright! You are good to go on salt and making chlorine. Double check the cya and aim for 60-80 on that. Then all we need is some hot weather!

Off the record, I might have put too much salt in my pool one time. No witnesses though, so I'll deny it.

 

[Propbndr]

New numbers after a 10% drain and refill.

FC 7.0
CC 0
PH 7.5
TA 130
CH 200
CYA 80
Salt 4200
Temp 66 (down right balmy compared to 50 at opening)

Now I think I will take a wait and see attitude and see what mother nature does.

 

[pooldv]

Yep! Very nice, good to go.