The absolute essentials are:

Sanitizer - for killing bacteria. Chlorine or bromine are the only options deemed safe by Health Canada.

Shock (Oxidizer) - for breaking down organic contaminants that sanitizer struggles with.

pH (up, down) - for balancing acidity of water.

Alkalinity increaser - for controlling pH stability. pH down is the same as "Alka down"

The general rule of thumb is 30 minutes for chemicals like chlorine, bromine, pH/Alkalinity balancers; however after a shock treatment you may want to wait, you may want to wait 60.

Wipe around the waterline of your spa with a sponge weekly. Rinse your filters weekly, clean monthly, and replace yearly. You should also drain, deep clean, and refill your water 3-4 times a year.

Yes, since a hot tub or all season pool stays running all the time it would grow bacteria quickly without a sanitizer. pH and Alkalinity balancers are necessary as water acidity can cause damage to your spa if left unchecked.

There is no better option, it comes down to personal preference. We usually recommend chlorine as it's less expensive and better suited for outdoors. Learn more in our chlorine vs bromine article.

White flakes are usually a buildup of calcium scale (from hard water); use a stain and scale controller to prevent.