do you still need to cycle tank if your upgrading?

[Sam.Caz]

I was wanting to get a larger tank right now I have a 36g bowfront and want a bigger tank. but my question is came I just transfer all my stuff from one tank to the new one right away or do I have let the new tank cycle? I've had my tank for three onths and everything is doing great.

[Mr Cob]

You'll get a cycle either way. Depending on how you do the transfer will determine the size of cycle you go through. Corals and fish can typically handle the small cycle that tank transfers go through.

[Europhyllia]

how much bigger do you want to go?
I went from a 30g to a 125g. It was a bit of an emergency situation.
I did not use new liverock but rather got precycled dry rock from marcosrocks.com (no decaying organic matter on it) and just seeded it with the pieces of liverock I was transferring from the 30g.
I also got some Fritz bacteria to help it along (it's refrigerated and shipped overnight. expensive but worth it more so than the bottled stuff with unlimited shelf live that really isn't live bacteria anyway.)
I never experienced a really noticable cycle with that method as far as elevated ammonia or nitrite goes but still got the typical cycle related algae blooms (see my tank evolution thread below).
If you wanted to add real liverock I'd cycle that one first to get rid of the die off.

[StevenSeas]

^^^^ dang beat me to it Rob
edit: and Karin LOL

[Big_Pun]

do you plan to use the sand from the old tank, also are you saying the 36g is only 3 months, if so that tank probally isnt fully cycled. do you want to transfer all in one day? or can you store stuff in bins with pumps and wait a couple days

[Europhyllia]

36g is only 3 months, if so that tank probally isn't fully cycled.

Yeah 3 months most likely still has some stuff going (algae blooms, etc. on but should have a usable bacteria population.

[StevenSeas]

Yeah 3 months most likely still has some stuff going (algae blooms, etc. on but should have a usable bacteria population.

Usable yes, but not fully developed hence the algae blooms, so with it not being fully finished I would cycle the other tank first for a few weeks atleast so that the new tank has atleast enough of a bio filter (be it algae or bacteria) to support itself and then put all the rock and sand from the 36 in there for a few days then the fish. of course the plan doesnt take into the amount/sensitivity of the livestock, size of upgraded tank etc

[Europhyllia]

Ah see to me the usability of the established filter seems much more related to the amount of organic inputs than to the tank surrounding it.
If he uses his established sand and rock and only adds what he has now as far as organic/nutrient pollution goes (no increase in livestock, pre-cycled dry rock, etc.) then it would seem the filter would be at the same level in the new tank as it is in the current tank. No?
As I said before big difference would be if he added stuff that contained additional organic matter/nutrients such as decaying new liverock, etc.

[StevenSeas]

I agree with that, hence my suggestion of cyclin first then add the current live filter. It was my assumption of his use of live rock and sand to finish the upgrade. I forgot about the possibility of using somethin like marcorocks. I also agree with what you said but think that its idealized b/c the larger volume equals less contact time W/ the biological filtrants, probably not much of a big deal though...