Couple of cycle questions

When I upgrade to a larger tank I'm wondering how big of a cycle (if at all) I should expect?

I'm going from a 20g DT with 20g sump/fuge to a 75g DT with 20g sump and 20g fuge. I'll be using all of my rock with another 50 or so pounds of dry rock. Will be using all new sand.

Should I use the 40 gallons of water I have now, or should I use all new?

If there is a small cycle, what should I do with my fish, coral, and verts?

 

I would use as much of the old water as you can; it'll be less of a change for the livestock that way. I would try using ammo-lock or similar if you end up hitting some ammonia, as that's a good temporary solution.

 

I upgraded from a 75 to a 150, used all of the live rock in that tank plus another 100 pounds or so of base rock. Used new sand in the DT and put my old sand in the fuge. I also used as much water from the 75 as I could and I never saw a measurable cycle. I put all livestock in the new tank the same day.

I did get a small diatom bloom that lasted for about a week or so, but other than that....it was pretty smooth sailing.

Good luck!

 

Will do. Thanks, wasn't sure if using the old water was a good idea or not.

 

Thanks.
Didn't think about using the old sand in the fuge. I though re-using sand was bad? Maybe in the fuge it's ok but in the DT it's bad?

 

If the sand has any age to it, it would probably be in your best interest to get new sand. We upgraded after only 2 months (and run a SSB, not more than an inch or so) so our sand was still fairly new.

 

Yea I've had the same sand for a couple years now. Guess I'll just throw it all out and get all new for the fuge and DT.