Water level
Keep the water at mid-skimmer. If it drops too low, the skimmer sucks air and the pump can lose prime; the salts also concentrate and the pH goes off. Top up what evaporates.
Foam
Usually from too much product (foaming algaecides), lotion/oil residue or very soft water.
- Check the algaecide dose.
- An anti-foam fixes the symptom; the cause is solved with filtration and balance.
Scale / deposits and "sparkly" water with buildup
Usually high pH and/or hardness (scaling water).
- Lower the pH into range and watch the hardness.
- Use a scale sequestrant and brush off the deposits.
Red eyes and chlorine smell
It's almost never "too much chlorine": usually unbalanced pH and chloramines. Fix the pH and shock the pool.