Adding a sand bed at a later time.....

[lpsreefer]

Doing it adding small amounts but remember to rinse the sand first the super fine powder sand plays havoc on a system.
I ran I test in my little tank by putting sand in a container put it to te down of my tank under down after rinsing and then just let gravity push the sand out worked out well. But it was only a 20 gallon with damsels. Two pieces of live rock. Didn't cycle or have any spikes. The test was only a week long.

You just gotta avoid the cloudiness by stirring to much sand up.