Taking on an established tank

[Tracyd]

Hi, we have been offered a small marine tank that we would like too take on. However I am puzzled by the water issue. We have had a marine tank many many years ago, before the equipment and salt water mixes we have now. We have been told that when we get the tank back home and it includes fish etc, that we need too but some new salt mix rather than use the water that was already in the tank. I was told years ago that you needed to put the old water back, so as not too stress the fish while the tank settles . So can you just put new salt mix in or do you use the old water. Thankyou

 

[BeardedDragon21]

How far are they traveling? If it's a long trip then it's better to not reuse the water the fish are transported in as the ammonia levels can spike after opening bags after transport. However if it's a short trip across town I don't see any reason why you couldn't use the same water especially because they are going back into their same tank

 

[vetteguy53081]

Blend it. Salvage some of the old water and combine with new, BUT .........but ....... by mixing all new water, you have control over salinity rather than trying to match the new with the old.
Other concern would be differences in others water and yours (ph, chlorine, tds, etc)

 

[Lost in the Sauce]

I have no evidence to point to what's right but recently when I took over a fully established 120g reef tank, I transported it and reused about 60g of tank water and supplemented with saltwater matched to salinity, temp and ph.

 

[BeardedDragon21]

I have no evidence to point to what's right but recently when I took over a fully established 120g reef tank, I transported it and reused about 60g of tank water and supplemented with saltwater matched to salinity, temp and ph.

Good outcome?

 

[Lost in the Sauce]

Good outcome?

Yes. I didn't lose any corals in the transfer.

There was one fish death after a few days but I don't attribute that to the water as much as the stress of the move.

The tank did not re-cycle. Just picked up where it left off.

 

[Tired]

All the beneficial bacteria lives in the rock, not the water. A tank won't cycle if you change out all the water, otherwise those picos that get 100% changes weekly would be constantly full of ammonia and death.

Use all new water to avoid any gunk that might have been stirred up while taking things down, and drip acclimate the fish. A few hours in buckets or bags won't build up enough ammonia for them to need out of those bags immediately, so this is a situation where drip acclimation is good.

 

[Cell]

Who wants to haul all that water around for minimal benefit?

I'd make a fresh batch of water at home, heavily rinse the existing sand if there is any, and have a semi-fresh start for the tank.

 

[Just John]

If you don't have the RODI water or salt you need right now and need water immediately, your local saltwater fish store probably sells 5 gal. jugs of pre-mixed water.