[opiumpipez]

head loss is basically the amount of pressure lost at a given height.

so for example. my eheim 1260 is rated at 640 gph (approx) at 0 head. then, as you increase the distance between the pump and the return bulkhead there will be a proportionate amount of pressure loss (due to gravity and distance).

if you choose stock SPS, you will need quite a bit of flow (anywhere between 40x and 80x your total tank volume).

so for example,

in my 75 gallon (85 gallons will sump and rock displacement) i am running a tunze nano stream (900gph), vortech (2700ggph) and return pump (400gph at 3ft head).

within the tank i have 4000gph flowing randomly. my TURNOVER is still at the 400gph. therefore, i have abuot 50x the amount of flow when compared to my tank volume.

if you choose to stock lps and softies, you can reduce your flow rate to probably 25-40x (check with other members, i have never owned an lps/softy dedicated tank)

anyhow, the flow that i have in my tank virtually eleminates all dead spots and does not kick up any sand.

let me know what your budgetary contraints are and stocking ideas and i can at least point you in the right direction.