The TF-100 XL differs from the TF-100 by containing double the amount of R-0870 and R-0871.  These two reagents are used in testing very accurately for high levels of chlorine....something you will need to do frequently if you have a green, swampy pool or you are converting from baquacil.
 
It contains 7 tests.....each designed to help you understand the condition of your pool water.  Combined, these tests give you a perfect "picture" of your water.  The results will let you know, even if your pool is perfectly clear, that you may need to make some adjustments to keep it that way.

The tests are:

1. Chlorine Test (OTO) very reliable for detecting the presence of chlorine in your pool - normally used daily.  The most common cause of pool water problems is lack of chlorine.
    
2. pH Test - This important parameter of your pool water should be tested frequently.  Too high and you can form calcium deposits (scaling).  Too low and you can damage your equipment.
    
3. Chlorine Test (FAS/DPD) - This test seperates the TF-100 from cheaper "bargain" kits......most simply do not have this test.  Measuring chlorine VERY  precisely, even up to 50ppm+, this test is indespensible to a pool owner.....especially when correcting pool water problems.
    
4. Combined Chloramines Test - CC's are a good indicator of the need to shock your pool.  The TF-100 can measure CC's down to .2ppm.  Cheaper kits will not have the CC's test.
    
5. Calcium Hardness Test - measure the CH of your pool water and your fill water as well.  This allows you to control and manage this important parameter.  Excessive calcium contributes to scaling and too little can damage your plaster.
    
6. Total Alkalinity Test - TA buffers your pH.  While there is a lot of latitude with this parameter, close monitoring (testing) several times during the summer is essential.
    
7. Cyanuric Acid Test - CYA protects your chlorine from sunlight.  It must be kept at the proper level to be effective.  Again, the cheaper kits do not perform this essential test

All packed carefully in a customizable, large plastic case, these kits come complete with all the chemistry and hardware you need.   Thorough instructions will guide you through each test and provide you with guidelines to tell you what levels are acceptable.
 

There is a waterproof Recording Log on the front of the kit to record your results so you can monitor and/or counteract any trends developing in your pool water.
 

If you would like even more detailed information on the tests,  just click on the test kit instructions on the left.