A simple urinalysis test can tell a lot about your condition which include pH of the urine. A high pH (alkaline) can cause various different types of crystals to form in your kidneys and cause the sediment that you experience. A change in diet, your health, medications and or vitamins could cause your urine pH to go up and cause your noticeable urine sediment. Of course a full urinalysis will tell your doctor much more information about your condition than the pH alone. Analysis of your urine sediment (crystals) can also be helpful.
About 35 years ago I started taking large amounts of vitamins and not enough water. After about 6 months three kidney stones had formed in my kidneys. A urologist told me to stop the vitamins, eat a “normal diet” and drink lots of water. For a while I peed a lot of what looked like sand and then I passed the stones the biggest of which sent me to the hospital. The biggest stone sat in my bladder for a couple of months and then I just peed it out with no pain. Since then I have had no stone formation with mostly healthy looking urine.
Perhaps something as simple as drinking adequate water and or changing your diet might solve your problem.
Good health!