Just water, how long is too long?

I finally have all of my equipment and plumbing assembled, have the RO/DI system working. Only problem is that I am woefully depleted of cash for the moment. :(
Can I fill up the tank, sump and refugium with salt water and let the whole system run for a while before adding anything?
This is a 125 gallon tank and it will require a substantial amount of liverock. I would like to get the $$$ together and buy it all (or most) at once to cycle the tank. My husband wants to just put
in it, even if it is just water. I admit, I would be nice to test all of the equipment. plumbing, water tests for a while.
But how long is too long? I am worried that I will just encourage some strange algae growth or worse it I let this run for a long time w/o stuff in it.
I have four bags of aragamax sand that I could throw in the refugium or tank. But, I am planning to order live sand with the live rock.
I figure that it will be a month or two before we get the ls/ lr.
I appreciate all suggestions and advice.


add the sand and do a fishless cycle with a raw shrimp. then you can add the live sand on top of that when you have the money


agreed go ahead run it and start cycling it with raw shrimp or even put some flake in to decay, it will give you a head start for when you get your lr and sand. becareful though when you add the live rock and sand you will probably get a mini cycle. so keep any fish out for the time being.