Tile, large flat stone=> it's going to be very wet and humid in there. Lots of open top warm tanks, small little room etc...........
I would suggest adding the tanks carefully throughout the home.
That's the point of the tank.........to add to the living space, not cloistered off in one secret spot. If you have one large tank etc.......then this might be a good idea, but not with this many.
You'll also enjoy the lower humidity and not get mold or have to buy a dehumidifier. I promise you'll have to use one 1/2 the year if not more otherwise in the small room.
Everything in the room needs to be anti mold.
Well, you'll learn
Also, it's tough to take pics with too much overloaded stuff in one room.
You own a home(also known as a money pit) so use it and plan carefully before setting the tanks up. Hard plumb the tanks, add drains, collection cisterns for irrigating the landscaping. Add an RO reservoir tank somewhere remotely, have wastewater irrigate etc.
Do you enjoy looking at the tank while you are sitting for dinner? At the desk working? As you walk in the front front door etc? Do you really want the tanks all in one room?
This makes sense for some reasons, but mostly if you are breeder etc.
But not for display tanks....... which sounds like what you are doing.
Clutter is hardly the "ADA" way or sukiya living.
You have more space if you spread things out.