I've looked all over and I'm not really finding a definitive answer. I weigh around 205-215 and I lift about 5-6 days a week.
I grab a gigantic jug, fill it, and drink until I can't/don't anymore. I walk 15 miles a week and lift 3 days.
what i've heard is if your piss is yellow and/or it smells you're dehydrated. if it's clear and odorless you're good to go. i read this out of a survival manual so take that FWIW
I'd start with 8 glasses. I think that's the blanket amount they say all people should drink. Maybe move up to 10 or 12 considering your size, if you can do the 8 rather easily. just dont be one of those gym rat weirdos who carries the enormo jug with them in the gym.
For most of my adult like I have worked in construction. A large part of that involved working directly in the sun all day. No matter how much you hydrated you quit sweating by about 2pm. I remember once listening to a comedian busting on 44 ounce drinks and who the hell would ever need all that. I laughed and thought.. he's never worked out here or he would know! You come into 7-11 and fill the 44 ounce cup.. immediately chug 3/4 of it, fill it up. Go get chips etc while drinking about half, fill up before going to counter. Nothing but ice left by the time you get back to the job, fill it with water and take it back to work with you... drink it all while still cool. I routinely drank well over two gallons of water plus 10-12 beers a day and peed yellow until 9pm. Down at 11, wake up again at two a.m. thirsty because the alcohol was burning off. (the water got the job done, the beer got the divorce done.) I firmly beleive the body adjusts to the rapid loss/replace cycles of water. You become conditioned and can still perform at a high level over a larger range of hydration levels. Keep your potassium/maganese levels up and you won't cramp easily even dehydrated. This conditioning served me well into my early 40's when I raced mountain bikes, I think it is like "muscle memory." I never had hydration issues and really never sugar bonked either, lungs were always the limiter. I agree with gapper, I think the best advice I can give you is color of urine. Minimum 8 glasses a day, when you work out aggressivly hydrate until it is clear, you need to flush the toxens. Eat bananas.
Are you taking any supplements? Certain supplements, such as creatine, require you to boost your water intake regardless. For someone who works out regularly at that weight I would say 1 - 1.5 gallons a day.
No supplements, but I eat a ton of food so I'm pretty much always thirsty. I think I have a high body temp too bc I'm always warm no matter where I go.
Do you drink a lot of caffeine? every 8oz of coffee/heavy caffeinated soda requires about an extra glass of water. Chronic dehydration can cause high blood pressure and eventually serious heart problems, so if your pee is dark yellow almost orangish (vitamins can make it turn a bright yellow with a greenish tint), then you need to continuing to increase your H20 intake daily until peepee is virtually clear. LOL. Pure water can also go through you so fast that your body doesn't have time to absorb it all, so you might want to throw a few splashes of sea salt into it each glass (or premixed in a large jug) so you can retain it longer.... and it can take weeks to properly rehydrate itself.