HI,
Thanks for useful videos!
We have an in-ground pool with a liner and a sand filter. When algea took over and could not be removed from water, we emptied the pool. Found a coating of light brown grit stuck to pool bottom. Also found minute specs of sand in the returns after water goes through filter. We are removing grit tediously with a water jet (Karcher). What to do once that is done?
1. Empty sand filter to inspect the laterals and bulkhead fittings?
2. Make repairs and refill with new silica sand?
3. Fill pool and treat water?

4. WHAT ELSE TO DO so that we can repair this and avoid a recurrence?