Restarting an established tank with BTA

[Corey's Aquaworld]

Hello all. I have a 40 gallon Fluval "cube" that I picked up a few months ago that is well established. Its been running for 4-5 years and I didn't have any issues taking t down to move it to my house. It isn't drilled so it has a Tidal 55 HOB filter for mechanical filtration, as well as a Hygger 300W heater, and 2 Hygger powerheads (total gpm around 1300-1400). When I brought it home it's parameters were very far off and I've since stabilized it and my parameters are with in tolerable range except for the nitrates and phosphates of course. Working on that with water changes.

Currently it's stocking is

Fish
2 occelaris clowns, a coral beauty, a blue damsel (these first 4 fish came with the tank) and I've since added a bi-color dottyback and a lawnmower blenny.

Inverts
Banded brittle sea star
5 emerald crabs
8-10 blue legged hermits
4-5 peppermint shrimp

Coral
BTA
Goniopora
and 4-5 random SPS plugs that I forget what they are

The reason I want to restart is not only because there's turf algae everywhere (it has gone down significantly since I bought the tank and have been doing maintenance on it so the algae isn't the biggest issue) but because I just don't like the rock piece that's in it and the sand is old and gross looking.

How can I safely replace the sand and rock without 1: crashing my cycle, and 2: harming my corals.

If I can't replace both at the same time I'm going to replace the sand first then, because that's the biggest issue for me.

Thanks for your help!

 

[The_Paradox]

I would cure your new rock in the sump for a few weeks then start swapping it out to the top. That or put in the new rock and throw the old rock in the sump. As for the said if you can’t just vacuum it, I would replace it last.