i have one as well, from what i've observed in keeping him (he's about 3 feet now) i feel like your monitor would really enjoy the extra room and take advantage of it, they are very curious active guys. i would aso recomend putting a decent sized water container, i have a 35 gallon tub (in line with the dirt) with a waterfall and some crayfish and random fish. more tha just making the habitat more aesthetic, but he really enjoys it. he sits on the ledge where he can just stand in the water sometimes, but i also see him diving quite often,like swiming underwater and under the ledge. he also props his head up on this one rock and swims like he's on an aquatic treadmill. i also have a lot of branches for him to climb, which he also loves to do, in fact his favorite hide is a gourd proped up in the branches. in all, im saying take advantage of the room because he will appreciated and use it, especially as a little guy... think about it, in the wild he has an entire forest to explore.
hope this helps you out,
-jake
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"I live for the nights I'll never remember with the friends I will never forget"