Changing out sump

So my current sump on my 29g tank is a 10g tank with no divides in it and has a hob refug. Soo I built a nice new one with glass dividers in it and its own refug. When I do my WC on wensday. The refug has a 3-4 in sand bed should I just toss the stuff in or can I switch it over.the tank is maybe 3-4 months old.
Im doing this to slim line it and make it more organized.

My plan is to shut tank off let it drain into sump
Drain sumpm
Then pull everything out and do a clean on everything it is after all the 3 month mark and skimmer and that needs to be cleaned
Then pull sump out and the hob fug
put new sump in
Then put the mixed water and put everything in it and reactivate after I make sure the salt lvls match and temp match and watch my new sump fug work.
Should I get anything for nitrites and ammonia just incase a new tank syndrom wants to go. Tank is fully cycled its self but idk with such a big change anything can happen

 

Is there anything I should be worried about

 

Slim chance of having any kind of cycle with such a new tank. But if your gonna disturb the sand then it's best to change some water in sump after its filled. Just so any kind of disturbed sediment won't go into the tank.

 

Well I plan on putting water in New sump and let it settle for a while then start it up