switching from 20 gal to 100gal w/ sump

[catchndolphn]

im fixing to get a new 100gal and transfer my rock fish and sand to my 100gal to "seed it". curious on how cycling works when doing this.

[melosu58]

IMO I would go with new sand and seed a little bit of your old sand. Your old sand has alot of nasty stuff in it and it will cause a spike in your tank if you put it all in. Unless you have some LR in the old tank to transfer or some cured LR to put in there you`ll need to cycle again. When I transfered my 55 to my 125 I didnt transfer any of my sank. Just used the carib brand and bought some true LS from the LFS to seed it. Good Luck on the transfer

[alaher2]

I agree with Mel, one thing also, is don't rush into adding fish just yet and make sure the tank is properly cycled. Also make sure the sump is working for a few weeks, otherwise if there are any leaks or excess stress it could be a disaster waiting to happen.

[catchndolphn]

how big of a sump should i run? how many gph? I have cured live rock approx 40lbs from the small tank. and planned on switching to a smaller sized sand then the crushed coral.

[roka64]

I agree with the rest, don't add your fish to the new tank until it is fully cycled.
Can you fith the 55 under your tank, for a sump?
CC, I have never has a rock fish, but I bet he wouldn't like a CC substrate. They tend to bury themselves in the sand and CC can possibly injure them and will also limit any other sand stirring/sifting critters you might want.
Remember, the CC will stay on the top of the sand. If you mix the two, it is hard to clean the CC without sucking up a bunch of your sand. Trust me, I did that same combo and ended up just removing the CC. There are folks that love the look of CC and are perfectly happy with it, I wasn't.

[melosu58]

At the very begining I had CC and even though alot of people like it I was not satisfied with it.

[catchndolphn]

not sure if a 55 will fit or not. dont have exact dimensions of stand yet.