Sand for tank upgrade

[PAdrone]

I want to move from a 75g to a 120g. The 75 has been established for probably 8 years. The plan is to move all the live rock and attached coral to the 120 first and then ad new sand or live sand. Along with as much water from the 75 as possible and additional water. With this cause a cycle? Any recommendations?

 

[Tamberav]

Should work fine. Maybe something very mini like a small diatom bloom or such.

 

[Reefering1]

Why not add the sand 1st and let the dust clear before adding the corals??

 

[PAdrone]

Why not add the sand 1st and let the dust clear before adding the corals??

I don't want the live rock sitting on the sand. Rather it sit on the solid bottom. The corals are already established on te rock

 

[malacoda]

It'll be fine. There won't be a new cycle as long as you're moving your rock over. And you'll avoid the issues of a zero-nutrient tank by moving a good amount of water from your 75g into the new 120g.

You don't even have to buy new sand. You can just thoroughly rinse you're existing sand just as you would a new bag of sand (tap water from you hose is just fine if you're on a well or a lot of RODI if you're on city water (because of chlorine/chloramines). It will even keep some of the beneficial bacteria.

I've done this 3 times now after tank upgrades/moving to new homes.

The worst I've ever encountered is a brief touch of diatoms and dinos after adding new 'dry' sand to fill out the bottom of the tank (it was a 65g to 120g upgrade so I need a good amount of additional sand). They only appeared in the areas of new sand. And after 2-3 of the tank settling in and regaining its balance, they vanished, never to be seen again.