I haven't secured mine... been running for about a month and a half now without one. I think once you get it figured out, you should probably put them on though just for safety purposes. If mine falls, it's just going to fall off the tank though.
FWIW, my sand never clouded my tank in the least. I doubt you'll even have anything more than a haze for a day or two if you put the sand in after. Even without rinsing it (as mine was super super clean... I'm sure yours will be to).
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