Moving fish from a smaller aquarium to a much larger one.

[nickzaver92]

Hi everyone,

I was hoping for some advice on my situation. I currently have a 40b that's been established for as long as I can remember, and is being used as a grow out for my 3 Goliath tigerfish. They are juvies (about 3"), very healthy, eat anything and everything that hits the water. Water parameters in this current tank are near perfect (0 ammonia, 0 nitrite, 10ppm nitrate at most). I wanted(and needed) to upgrade their tank, so I just picked up a 180 gallon for them(6x2x2). The 40b is being filtered by a fluval fx4, and the tank also has sand substrate, a few small rocks, and small pieces of driftwood with Anubias growing on them(nothing that the tigerfish can run into and hurt themselves on). I know I can just go ahead and setup the 180, throw everything over to it, and add the fish, but would that be enough? Would the bacteria in the filter of my fx4 be good enough to make sure my fish are ok when moved to a much larger volume of water? I would think yes, but just wanted some opinions/insight. Thanks everyone.

 

[esoxlucius]

You are correct. Just transfer everything over and you are good to go. Just to ease any initial worries you might have you can always test your water for the first couple of days, but i'm sure you'll be fine.

 

[Rocksor]

Use 100% new water.... no need for the old water in the 40b.

 

[troublesum]

I was always under the impression that the filter may not have enough BB to support the larger amount of water you will probably go thru a small mini cycle.
more water volume dilutes the fish waste
wait for the scientists to log in....LOL

 

[esoxlucius]

I was always under the impression that the filter may not have enough BB to support the larger amount of water you will probably go thru a small mini cycle.
more water volume dilutes the fish waste
wait for the scientists to log in....LOL

You are correct to a certain degree. BB are on every bit of submerged surface in the aquarium, but mainly in the filter. So if he transfers EVERYTHING over then he will be transferring a very very high % of the BB over to the new tank. This should be enough not to cause a mini cycle, I'd certainly be confident anyway.

The only BB that he won't be transferring over are any BB that were on the glass for example of the old tank.

To be extra safe to compensate for this the OP could refrain from feeding for a period of time, or use some bottled BB just to be sure (not that bottled BB works for everyone, each to their own on that one).

I'm very confident that he won't have any problems at all if he transfers everything over and adds the fish. Also, as already mentioned, transferring the actual water from your old tank doesn't really help with the BB situation as the BB are not in the water column, they attach to surfaces.

 

[nickzaver92]

You are correct to a certain degree. BB are on every bit of submerged surface in the aquarium, but mainly in the filter. So if he transfers EVERYTHING over then he will be transferring a very very high % of the BB over to the new tank. This should be enough not to cause a mini cycle, I'd certainly be confident anyway.

The only BB that he won't be transferring over are any BB that were on the glass for example of the old tank.

To be extra safe to compensate for this the OP could refrain from feeding for a period of time, or use some bottled BB just to be sure (not that bottled BB works for everyone, each to their own on that one).

I'm very confident that he won't have any problems at all if he transfers everything over and adds the fish. Also, as already mentioned, transferring the actual water from your old tank doesn't really help with the BB situation as the BB are not in the water column, they attach to surfaces.

I was thinking about dumping in a whole bottle of seachem stability or the fritz just to be safe.

 

[jjohnwm]

The amount of waste produced in the tank is the determining factor that controls the bacteria population. Add more fish...produce more waste...and the population increases in response to the additional "food". Move the same fish to a larger tank, and they will produce the same amount of waste as before, so moving virtually all the bacteria with the fish (which is what you are accomplishing) means that you are essentially enlarging the tank they have been in all along. The cycle remains unaffected.

In actual practice, you will lose a small percentage of those bacteria as esoxlucius stated, since some are living on the glass, etc. and cannot be transferred. But that is a tiny percentage of the overall population and will be replaced very quickly. Maybe feed lightly for a couple days if you wish, but you shouldn't have any problems.

And for goodness' sake, don't keep any of that old water!

Three Goliaths in a 40? Yikes. In a 180? Slightly less yikes, but still...