Transferring Cycled Tank To New Tank

[Watcher74]

I currently have set up what I was told was a 20 gallon tall tank, 18" tall 20" long 10" width, but according to calculations apparently is only a 16 gallon.

I had a Duetto 100 with gph of 90 and which I was told was not enough filtration. So I've purchased a Fluval 204 cannister filter with 180 gph to supplement my Duetto. I realized that with this extra filtration I can set up a 30 gallon tank I have.

Within a week I plan on transferring my fully cycled 16 gallon into the 30 gallon tank.

I currently have 1 angelfish, 12 neon tetras, 1 boesami rainbowfish, and 1 ramshorn snail.

I will use everything I currently have in the cycled tank for the new one(decorations, duetto filter, gravel, etc.) plus the new filter.

Can anyone give me any advice on the best way to do the transfer without harming my fish or stressing them anymore than absolutely necessary?

Thanks for any replies.

[JesseJ]

I would set aside an hour or 2 to do this and make sure that you will have no interuptions.

Siphon out a bit of water into a large, well rinsed bowl. Put the angel and the snail in here and cover it with plastic wrap to keep the fish from jumping out. Get another bowl for the neons and the Boesmani and do the same thing.

Now, move the contents of the tank over. Put in the gravel and decorations and then all the water from the small tank. Top up with conditioned tap water. Wait for 30 - 60 min to let the filters strain out large wastes and to get the temp set. Then gently add the fish to the new tank starting with the neons and finishing with the angel.

If you do this quickly enough the bowl water won't cool down very much and there won't be very much stress on the fish.

[OrionGirl]

You don't have to worry about moving the water--the beneficial bacteria are not free floating in the water column, but rather are on the objects in the tank and the filter. Use clean, conditioned water that's close to the same temp/conditions, and you don't import any nitrates.

I also wouldn't use plastic wrap to cover the bowls--this will limit the fish to the oxygen trapped inside. A towel will work, or, use a clean cooler. The lid can be set on top to prevent jumpers, but still allow some air movement.

[Watcher74]

Oriongirl,

If I use all new conditioned water won't I also be removing the ammonia and nitrites that the beneficial bacteria need? It seems that if I did that, that a portion(large or small) of the bacteria may be lost.

Wouldn't that set off a biological hiccup of some sort that might shock the tank?

[OrionGirl]

Not really. If the tank is cycled, the fish will introduce the needed food source as soon as you put them back in the tank. The amounts of ammonia/nitrite present in the water of a cycled tank are very low, so removing that small amount--but immediately 'replacing' it with the fish, won't hurt the bacteria. If you were to leave the tank running without fish for days, yes, the bacteria would starve. A couple of hours is not a problem.

[Watcher74]

Ok, how about this then. I set up the 30 gallon with the Fluval, add the extra gravel I'll need, and let it cycle for a couple days letting the temp match the temp in the cycled tank and the chlorine to dissipate.

I can syphon some of the water from the cycled tank into my 10 gallon tank I use for partial water change preparation with my extra bubble wand and heater in it.

Then transfer the fish into the 10, move over all the stuff from the cycled to the new, then put the fish in.

....that seems like the best way. Is there anything else I should consider here? If my angelfish dies I'll be extremely upset. I want to make sure I don't screw this up.

[OrionGirl]

That will work just fine. Often, people upgrading need to put the new tank in the same location as the old tank, so don't have the option of setting the new one up in advance.