Hi secimma:
Kidney stones are strongly linked to the diet, I know because my husband had them since his yearly 20s. Many folks develop uric acid stones while low carbing but you need to get the stone analyzed if you already passed one) or get a 24 hour urine collection test to find out which kind you have to adjust your diet accordingly. Water does help with formation of the stones but too much will overburden kidneys. If you are in a mood to get rid of them (or it) and if the size is small, i can recommend a supplement Stone Free, helped DH to pass one stone recently. But make sure that it's a small one, not large and keep some very strong pain medication around.
Regards,
Dina