Upgrading established tank

[bureau13]

OK, here's a question...if I upgrade, say, a 55G to something significantly larger in the 175G - 210G range...and say I use the water, live rock and live sand from the old tank, plus obviously a lot more new salt water and new (but cured at the LFS) live rock...do I need to go through any cycles prior to adding in my fish and corals from the 55? I should really be all cycled, right?

When I upgraded my original 29G to the 55G I just moved everything over, and it worked out fine. Never saw an amonia or nitrite spike and none of the critters seemed too bothered by it, but in the new case, the difference in size (and so the amount of new water, rock and sand) will be much greater.

Thanks,
jds

 

[mikenpam]

My understanding is that anytime you disturb the ballance of a tank there is a possibility for a cycle of some sort. For instance adding too many fish at once will cause a ammonia spike until enough bacteria grow too once again reach equilibrium in you tank. Alot will depend on how welll cured your new rock is and what may be released when your disturb your sandbed. My tank never had an ammonia spike but I still waited awile before adding my first fish. In your case I would just monitor your water parameters closely after transfering everything over to the new tank.

 

[bureau13]

For some reason I was never able to see this thread after starting it until I stayed up 'til 3 so I could do a search!

Thanks for the reply...the advice sounds good. I can't leave the old one set up fully while I fill up the new one, even if I didn't want to reuse the rock and sand (still not sure the sand reuse is such a good idea so maybe I won't) as the new tank will go in the same spot as the old. I could set up a "halfway tank" for fish but it would be cramped and probably have worse conditions than the new one, even if it does go through a small cycle.

jds

 

[Blown 346]

Re using the rock will be fine, use all of it, and all the water from the old tank.
I would get new sand, and take a few cups of the established sand from the old tank and put it into the new tank on top of the new sand. This will help seed the new sand.

Switching over to tht big of a tank I would bet you will see a cycle of some sort. You wont have enough bacteria to not have one unless you have alot of rock in the old tank.
But be prepared for the worst.