Where to place under T5's

[zrob4]

I have a 180 with 640watts of t5's that are six inches above the tank. I ahve a crocea that is on a rock about 20inches up in the tank and he is doing great, my recently purchased dersea I can't find a good high spot for and he is only like 6 inches up, at six inches up will he have enough light?

 

[Reef Bass]

How tall is your 180? Is that 6" up from the bottom of the tank, or from the top of a substrate (sandbed, crushed coral, clam cradling pvc, whatever)? How long do you run your lights?

 

[zrob4]

My 180 is 24 inches tall, and it is 6 inches above substrate of about 1.5 inches. Lights are on ten hours a day.

 

[Reef Bass]

I'd move him up.

My 100g is also 24" tall. I run 2 400w MH 10 hours a day and 2 54w T5 actinics 12 hours a day. My clams seem to be doing well on the 2-3" sandbed.

There's also a difference between having enough light to survive and being amply / optimally supplied.