50-Count HTH 6-Way Swimming Pool & Spa Chemical Test Strips $2.20 + Free Store Pick-Up (expired)

It's important that the test strip have both total chlorine and free chlorine, but at least the free chlorine is on the strip. This way you can tell if your chlorine levels are properly balanced, if not a high dose (shock/oxidizer) of chlorine is needed in order to get both levels balanced.

These test strips have a shelf life of about 12-18 months before they start becoming increasingly inaccurate. As with any other strip, dip for 2 seconds, remove from water, wait 10 seconds and you have a solid 10 seconds of good reading. After that the pads will become increasingly darker, thus improper reading. Make sure you do not store in humid / hot areas such as your laundry room or the toolshed outside. No test kit needed - just dip, read, write down your numbers so you can balance your pool or spa!

Some more helpful tips:

• Total chlorine of 1.0-3.0 ppm is ideal, up to 5.0 is fine during the summer. If higher, just remove your chlorine source (chlorinator, tabs etc.) for a short while to accommodate needs.
  
• Neutral pH is always ideal. 7.2 - 7.6 on the scale is great. If it's higher, add acid. If lower, add sodium carbonate (soda ash)
  
• Alkalinity keeps your pH from fluctuating, 80-120ppm is ideal. This number must be balanced according to your pH. You cannot have a 7.2ph and 200 alkalinity as high alk. will cause the water to become increasingly cloudy even if everything else is properly balanced.
  
• Total hardness (calcium) is a necessary mineral to have in the water. If too low this will cause aggressive water that will eat up plaster in attempt to pull the calcium from it. Wont affect vinyl pools. 200-400ppm is ideal.
  
• Cyanuric acid is your chlorine shield. Without CyA your chlorine will dissipate in a matter of hours due to UV rays. This chemical will save you a great deal of money on chlorine! 30-100ppm is ideal.

Hops this helps!

Everyone should read Pool School at http://www.troublefreepool.com
I'm not trying to criticize but 100 ppm of CYA is not good. You would need much more than 5 ppm of FC to properly sanitize the water because a high CYA requires more Chlorine. If you read the many posts by chemgeek he has done much research on the ideal level of cya and I think the current recomendation is between 20 - 50 ppm of CYA. This is accomplished by using bleach after you build up your CYA with the pool store stuff since it is combined CYA and Chlorine.

About the only use of test strips is a rough check for FC. Buy a taylor test kit if you want to do it the right way.

===•Neutral pH is always ideal. 7.2 - 7.6 on the scale is great. If it's higher, add acid===

hello, do you mind if i ask what kind of acid you use to lower ph? i use the ph-down from walmart but we have a large, nearly 1100 sq foot surface liner pool, and in our area ph readings are always high, so spending pretty good bucks each year to lower ph. any help appreciated. thanks.

Muriatic acid is often used for pools. I think you can also get it at half strength which would be safer. If I recall sometimes lumberyards even sell the stuff. You have to pour it very slowly over moving water and be careful not to get it on the liner. Goggles and gloves are a good idea too.