Measure sludge and scum with a sludge judge to verify pumping need

https://marcokbok187.capitaljays.com/posts/do-it-yourself-prep-as-well-as-pro-tips-for-correct-septic-tank-pumping-as-well-as-post-service-treatment

Step sludge and residue with a sludge judge to validate pumping need, then mix contents gently to suspend solids so the vacuum truck eliminates both layers, preventing blockages and premature refilling.