No chlorine reading in new salt water pool

May 29, 2012
5
#1
We have an above ground pool for about 20 years. We had to replce the liner this summer and decided to go to salt. We have had it up and running for 10 day but the test does not show any chlorine. Everything else looks good although I just tested and it showed the PH was a little high.
We have tried the test strips and today got a 5 way drop tester but still shows no chlorine. The water looks good. What could the problem
Barb
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
10,893
Houston, Texas
#3
Hi, welcome to TFP! Please post a complete set of test results and we will help you figure out what is going on with your pool.
 
May 29, 2012
5
#4
This is my test readings.
TH-200
FC-0
PH-7.8
TA-80
CYA-30-50
Our pool is a 27ft above ground with extended center to 6ft.e estamate 22,000 gal of water. We have a 1 horse power moter with a 19" sand filter.
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
41,197
Tucson, AZ
#5
Are there any indicator lights on your SWG (which one is it?)?
Does it appear to be generating?

Take a water sample from a return jet when the SWG is "generating" to confirm if any FC is making it to the pool.
 

Isaac-1

TFP Expert
LifeTime Supporter
May 10, 2010
6,711
SW Louisiana
#6
3 possible things come to mind:

1, your CYA is too low and all your chlorine is getting used up by the sun

2, combined with #1 while your FC was too low invisible algae has started growing and is consuming all your FC

3, your SWG is broken or there is not enough salt in the water for it to run

regardless of this, I would suggest establishing some chlorine in the pool with bleach, turn off your SWG and do an overnight chlorine loss test to see if you have algae growing. (chlorine level should drop by less than .5 ppm from dark at night until before sunrise if there is no algae) if it drops more than this you will need to shock your pool (read pool school link in upper right corner), then after that go back to solve your SWG issue.

Ike
 

frogabog

LifeTime Supporter
Jul 16, 2010
1,578
Portland, Oregon
#7
These are results from test strips, yes? Unfortunately they are very inaccurate, as you're seeing with the CYA result. The difference between CYA of 30 and CYA of 50 is enormous because of the great difference in chlorine that is necessary for those two numbers (and range in between).

With a SWG, you can't just start it up and hope the chlorine is enough. You have to use bleach at first to chlorinate till the cell begins to produce enough chlorine. Probably whatever it's producing right now is being used up immediately cleaning your water.

Do you have any way to test salt levels?

Right now, I'd go dose your pool with chlorine for the 50ppm CYA level (use pool calculator) and continue to test regularly and add chlorine to keep it there while you figure out the SWG. It might not be set high enough, salt may be too low, etc. but you can't go long without chlorine in the pool so just put it in. SWG CYA level should actually be in the 60-80ppm range, depending on your equipment (see your equipment recommendations).

EDIT: oops, been away too long. I forgot. Yes, the correct thing to do right now is deal with cleaning your pool and forget about the SWG. Turn it off, you're wasting your cell doing nothing. Dose the pool this evening with the SWG off, re-test in a couple hours see what happens. If you loose chlorine at night, you'll need to shock. Follow shocking procedures (with test kit) and when that's all done, turn the SWG back on and it likely will be able to keep up.

Must have for a pool, and while it always sounds like an extravagance, it's actually a necessity... A good FAS-DPD test kit. TF100 is the best deal around. Also get some salt strips while you're at it. The cell isn't always accurate.
 
May 29, 2012
5
#8
The SWG says it is generating. I did hold one of one of the strips and the FC shows 1/2.
How do I raise the CYA?
I have 2 bags of super shock. Should I add that?
 

jblizzle

Mod Squad
TFP Expert
LifeTime Supporter
May 19, 2010
41,197
Tucson, AZ
#9
1. Turn off SWG
2. Add bleach to get to FC 20ppm (shock level for CYA of 50ppm from Chlorine CYA Chart
3. Perform Overnight FC Loss Test

The result of that will determine if you should continue to follow the Shocking Your Pool process of if you are in the clear and can continue to diagnose the SWG and bump up the CYA.

EDIT: Although doing the OCLT in going to be impossible with test strips ... really need to get one of the recommended test kits.
 
May 29, 2012
5
#10
Ok, lots of good advise. Going to give this all a try. Thanks. This is a great site. Glad i found you. The pool places have just not been much help
 

Isaac-1

TFP Expert
LifeTime Supporter
May 10, 2010
6,711
SW Louisiana
#11
You probably should not use the "super shock" at least not until you tell us what is in it, different companies use different chlorinated chemical products and sell them under the name "shock" yours chould be trichlor, dichlor, or cal-hypo, each does different things to the water other than just raising chlorine. If you use liquid chlorine or bleach it will add chlorine and a little salt to the water, which is probably a good thing in your case.