Pretty much all of us agree on the test kit. It will be the most cost-effective expense you ever make on your pool.

I disagree on the round vs oval pool as I like to swim laps and you can do that in an oval pool but you need an AMAZINGLY big round pool to be able to swim laps. An 18x33' oval with 4' of water holds about 13-15000 gallons, but a 33' round pool holds 25-26,000 gallons---and it is FAR HARDER to vacuum the center of a pool with a 15-17' radius!

Plus it takes up more space in your yard. A well-built and properly constructed oval can easily stand for 20 years.

Just IMHO.

Carl