Balance the water chemistry before shocking.

Test your water first. pH and alkalinity need to be in range or the shock won’t work properly. Cloudy water usually means algae or fine particles, but adding shock to unbalanced water is just throwing chemicals away.

Check pH (ideal 7.4–7.6), total alkalinity (80–120 ppm), and calcium hardness. Adjust those first. Then shock with a good chlorine or non-chlorine shock. Run the pump 24/7 and clean or backwash the filter regularly. Brush the walls and vacuum when you can.

If it’s still cloudy after a couple days, you might need a clarifier or flocculant, but start simple.

Patience is the real chemical here — it takes time for the filter to catch everything.