I drink 1.5 litres of water as soon as I get up in the morning. Can I do the pranayams one hour later? Or should I stop drinking water in the morning? It is difficult for me to do pranayam in the evening.

You can do the pranayam 1 hour after drinking the water, but it all depends upon how you feel while doing the pranayam practice after having so much of water. It is not hard for the body to use up all this water in 1 hour but if you feel bloated or uncomfortable then you can reduce the amount of water or do pranayam a little later, but if you don't have any problem doing the pranayam then go ahead and do it after drinking water. Cleanse your internal organs with water and clear your mental and physical toxicity by doing pranayam