flow and sand

i was wondering, i am setting up a 120g tank, i would like to know how much water flow is good enough for this system, i currently planning on usig a mag 9.5 as a return, but iwant soemthing else more powerful, let me know. SO i was wondering about putting a dsb in the sump or should i use 100% clay for the fuge? can i keep the frags in there? or do i have to have a deep sand bed in the dsb? i will have around 4-5 dsb in my display.

 

I'll help with the question I know enough about. Enough flow for this system? The absolute most you can achieve without a sandstorm. Might sound kinda vague, but the return pump from your sump/fuge shouldn't be the one source of your tank water movement. Use whatever pump is appropriate for the sump/fuge, and to increase water movement in the tank itself, utilize powerheads; or maybe a closed loop system if you'd rather avoid powerheads in the main tank.

 

how much water flow? like some ppl were talking about the turn over rate, i dont know how they could come up w a rate, any formula? i am doing a mod to my k4 and hopefully it will bring out quiet a current

 

I had the exact same question. So I created a thread. I got many good answers. Instead of repeating it here, I'll give you the link. Check this out.