Filtering ray tank

[hbluehunter]

You're tanks 60 gallons more than mine (300 gal) but i use 2 FX5's, 40 gal sump, and a fluidized bed filter also.. For media i have 15 gallons of bio rings, 10 gallons of bio balls, and the bed filter.. Plus have 20lbs of crushed coral to regulate ph.
But if i had to do it over again i'd probably just use a huge sump or wet/dry.

 

[West1]

I am assuming it could be due to the water evaporating? Sump/box filter looks to be open, try to put something on top... even styrofoam and cut out whatever goes into the Sump/box filter. JMO

I agree w/everyone and I say add a sump to any aquarium