This test kit has an FC test, a ph test, a TA test and an acid demand test, cost of $33.75
The FC test will only test up to 5 FC, which is not high enough
You also do not have a CYA test (crucial) or a calcium test (not as crucial for you as you have fibreglass not plaster, but still need to know this)
I would just go ahead and order a kit from Clear choice. Has all the tests you need, also comes with standards so you can check your testing. Should last you a full season of testing and refills are available. Service and quick delivery from these guys too. My last order was on a Saturday and I got the test on a Thursday.
For you to get the salt water version its $158. Money well spent imho