just question about my 90g tank. i have a 20g sump so thats 110g of water. but i've got 200pound DSB and 120pounds of Live rock. so with all that extra stuff the water volume wont be 110g? what would it be about 80g or something. just wandering because i need to buy a chiller and i there is one to suit up to 100g? will that be ok?