*SWG will not generate and reads different than strips

[BigBrownLog]

i'm a lil confused i had a cya of 20ppm i put in 4# of cya yesterday and 4-5hrs later had it tested it was 50ppm. today had it tested and it was 30ppm. i have had no loss of water and did not add any. and swg has not been running well maby a few 5min cycles. i dont know if i read it correctly but does the swg consume your cya?

fc:3-6
ph:7.2
ta:100-110
cya:30
salt:3140
phosphates:200 is this ok i know it needs to be at 100 but what will it do at 200

also i added 4 40# bags of salt last night around 9pm and today the aquacheck strip said i have 2890ppm (the pool store confirmed that with 2900ppm thay have an electronic reader) my swg unit said i had 2100ppm and would not generate. I added 20# of salt 3hrs ago and strip says 3140ppm. the unit says 2300ppm. is that normal to be that different from the strips? i only ran the swg for the summer 2 years ago when i bought it last year i did not have time to take care of a pool.

i kinda need advice on what to do with the ta and ph. i read what i need to do but i guess it would just make me feel better to hear someone say how it needs to be done with my situation.

 

[mas985]

Both CYA and Salt can take several days to fully dissolve and mix with the water enough for the tests to become consistent. I would let things mix up well before doing anything more.

However, SWGs will tend to read lower than the salt strips but they are usually within a few hundred ppm. Check in a couple of days to see if things change.

For CYA, I would wait at least 5 days before testings. How did you add the CYA? This can affect how quickly it dissolves. Also the manufacture of CYA can make a difference in dissolving rates. I find that HTH (Walmart) takes the longest to dissolve.

 

[BigBrownLog]

i used a lil hotter than warm water to disolve 2# at a time i mixed the heck out of it cause i wanted as much as i could get rt away. then two hes later put in hte other 2# the same way.

and did i read it correctly? does the swg bring your cya down over time?

also what do you guys think about the digital salt tester http://www.monstermarketplace.com/General/Landing1103a2950.html

 

[JasonLion]

No, CYA does not go away over hours, or days. Over the course of an entire season your CYA level will fall a little, but nothing happens to the CYA level quickly unless you replace most of your water.

You are almost certainly doing the CYA test wrong in some way. The CYA test is fairly sensitive to proper lighting. It should be done on a sunny day but not in direct sunlight.

Digital salt meters can be good but only if you calibrate them to a reference solution frequently and they are well made to begin with. The inexpensive meters tend to break quickly.

Most of the SWGs out there track an average salt level over the last several days. They can take 24 to 48 hours to catch up when you change the salt level.

 

[BigBrownLog]

yeah i read that the cya test should be done with sunlight but i dont have the kit and i get it checked at the pool store with them doing it under fluorescent light inside. u should have seen the guys face when i asked him if he could do it outside in the sunlight.

and yes i understand that cya doesn't lower over hrs. i was asking if the swg in some way reduces your cya. in the sticky Waterbear wrote it says something about acid consumption. maby thats what the acid demand test is for, but i dont know what the acid demand test is for.

 

[frustratedpoolmom]

Nope, you are confusing the acid demand subject.

CYA levels are not affected by SWGs. You really don't want your SWG turned on until the water is properly balanced - you will shorten the life of the cell.

Pool store testing is notoriously inaccurate, especially FC and CYA levels. That is why we so highly recommend your own test kit, you can read about them in Pool School.