Watering down my OPKs...

🌹Rose🌈🎶 • FTM since 12/23/18 <3

So I have this thing about drinking lots of water... like between 3 and 4 litres a day. That's great and all except to have a reliable OPK I keep reading you should have more concentrated urine and not drink any fluids for 2-4 hours before testing. I find that part REALLY difficult. Does anyone else have this issue or any advice/suggestions? Thanks ^-^*