NEW Fuge, sand replace/refresh ?

So my existing fuge is about 3 years old, fiji fine sand, about 2 inches or so...Live rock ruble and cheato.
I am building a new sump/fuge/return and I am wondering the best way to go as for replacing/refreshing said sand.
I will keep my Live rock rumble and cheato. BUT..I was thinking of getting a fresh bag of live sand, mix it with about 2 cups of DRY crushed Coral that I have sitting here, as well as adding, lets say, 1 cup of the old stuff...for seeding purposes?
Any comments or concerns on this transition would be most helpful.
Thanx in advance.

 

Personally, I would use more than a cup of the established sand. Your rock will house a ton of beneficial bacteria but so does your sand. This would make me worry about causing a mini cycle in your tank. I would use atleast a couple pounds of it mixed in with the new sand. It shouldnt make much of a difference if the sand you buy if "live" or not because there wont really be anything "live" about it until its spent some time in your fuge.

 

cool...that was my thinking...(the mini cycle) no bueno! : ) But yes, I have the dry Crushed coral..and lets say half the old sand (would be a couple pounds or more...and then a couple more pounds of sugar or fine sand....This new fuge is a tad larger, so that would work....yah, that live chit is a bit over rated..lol Thank you norg. for your prompt reply. It should be within the next week that I do the do. : ) stay tuned.

 

Sounds like a great plan LG! Cant wait to see it up and running.