100 % Water change?

[Delphinus]

A fish-only tank with no fish?

Is the water foul? If not ... is there really a need for the water changeover?

I guess I'm more of the philosophy of "If it aint broke don't fix it". Unless you knew the water had issues, I'd be inclined to just start using RO as the top off and make future water changes with the RO, but wouldn't see a need to do a 100% changeout just because I was switching to RO.

Not knocking the 100% change though .. sometimes it's necessary.. But in this case I wouldn't automatically guess it would be necessary unless there are other factors to consider.

[Johnny Reefer]

Something doesn't jive here.
In one sentence you say you want to move everything to a QT tank.
In another sentence you say there is nothing in the tank.
Which is it?
If the "everything" you refer to moving is Live Rock and/or Live Sand and you plan on moving it back after the water change, then I would do a 50% water change....but then....why move "everything" in the first place?

Just some thoughts.

Cheers,

[McNasty]

There is no purpose in doing a 100% water change or even a 50 for that matter, if your tank has been running fine with np then just do a normal water change. Your substarte and rock will already be saturated with phospates and silica(think thats correct LOL) and doing a 100% water change will not change thos elvlv they will have to precipitate out over time.

[Matt]

A different sort of caution... make sure you break in your RO/DI well before you start this. The first fifteen gallons of water out of mine didn't taste very good.

Matt

[Deathstar]

I will just do a 50% change when I get my RO system on-line.

Sorry for not being clear I will have fish before I get the RO system, also I had fish in the tank last week.

Thanks,

Eric