Test the water before you shock it.

Yes, but the order matters more than you think. Most people dump shock in as soon as the cover comes off, and then wonder why the water stays cloudy.

Start with the cover. Remove debris first (leaf blower works great), then pump off standing water. Pull the cover carefully — that winter layer is nasty. Clean or replace the filter cartridges or sand before you run anything.

Fill the pool to the proper skimmer level. Then run the pump for an hour to circulate, and then test the water. You need to know your pH, alkalinity, and calcium before adding chemicals. Shock before balancing is a waste of money.

Once you know where things stand, adjust alkalinity first, then pH, then add any algaecide or clarifier, and shock last. Keep the pump running 24/7 for a couple days after shocking. Brush the walls and vacuum after the water clears.

Future you will thank you for not rushing that first test.