In which order should I use the cassettes in the SENSE S2 Cassette Combo pack?

The SENSE S2 Cassette Como pack contains the following:

• 1 x C5 Cassette - Measures pH and FC daily, plus CYA, Hardness, and total Alkalinity, lasts 29 days
• 2 x C2 Cassettes - Measures pH and FC daily, each lasts 58 days

How to use these cassettes after you have used the C5 cassette that comes with the SENSE S2

The SENSE S2 comes with a C5 cassette which should be used initially to balance the pool's water chemistry for the first month.
 
A SENSE S2 Combo pack should then be purchased for $65 which includes 1 x C5 Cassettes and 2 x C2 cassettes.  The Combo pack comes with this printed insert:

 
For the next 116 days, the use of the C2 cassettes from the 3-pack which measure the water's FC and pH each for 58 days should be enough to keep the pool's water healthy for the remainder of the pool season.
 
Depending on where you live, nearing the end of your pool season when you need to know water chemistry values for closing the pool, you can use the C5 cassette from the 3-pack to balance your pool's water chemistry before you close your pool.

Note:  For customers who require C5 cassettes year-round for their pool water chemistry measurements, 3-packs of the SENSE C5 cassettes are available for sale at the WaterGuru website for $65.