do you count how much food you put in and how many are gone the next morning? you can monitor your leos intake by doing that... if they're in the same tank and you're still concerned, try observing them during part of the night during feeding time over the weekend. if you can't do that, try feeding in separate tanks and monitoring the number of food items you put in and the number of food items are left the next day. with the water, you'll see them licking up during the night, but if you never catch that - if their urate comes out nice and solid, then they drink 
make sure you have an under tank heater because they need the belly heat for digestion. also make sure the tanks are 86F - 88F during the day and 80F - 82F during the night. the under tank heater is a must though 
good luck with your leos! take care 
[aimee]
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1.0 Albino Leopard Gecko (Melvin)
1.0 Black Lab / Pitbull mix (Mikey)
1.0 Blue Fighting Fish (Blue Balls)