It always depends on the person...mainly your body type, weight, age, sex, etc. so you can never tell...I usually don't have more than 1 - 1.5 litres of water while i'm on ex...
If you are dancing and sweating alot, drink regularly, otherwise you wont need it unless your thirsty!
i herd if you drink too much whilst "BUZZIN" ,it builds up in your head and you form little fluid sacks,the guy who told me this was serious but it sounds laffable
The risk is not that "it builds up in your head and you form little fluid sacks" It's that it dilutes the salt levels in your blood until you can't function. But here's the answer: "If you are dancing for hours on end in a hot and sweaty club or party then you should aim to drink about a 500ml bottle of water every hour. You should also think about drinking 'isotonic drinks' which will replace the salts and minerals you will be losing through sweating, or at least trying to eat a salty snack such as crisps or peanuts. Sip rather than gulp drinks. Don't just rely on drinking water to cool you down - take breaks, go to the chill-out, splash some water on your face in the bathroom. Make sure you urinate, even if it's difficult. " You might also get a little paranoid and think you Aren't having enough water, and drink to much which is why it's important to have salty snacks. info from http://www.ecstasy.org/qanda/q78.html
MDMA dehydrates you, but its not really too bad if your just sitting around, in somewhere cool. .5 liter an hour, (one thing of bottled water) But if your dancing in a club which can sometimes be pretty hot anyway, 1-1.5 liters an hour (two er three things of bottled water an hour.) Sports drinks are better for rehydrating you too, but they're expensive... so is bottled water.
