Switching tank over to new tank.

Well i'm gonna be switching my 36 gallon bowfront to a 46 gallon bowfront. Yes i know it's not that huge of a jump but anywho. I'm gonna be add more sand of coarse so i was wondering if i should put the new sand on the botton of the old sand or on top of the new sand? And i'm also gonna be putting a large CPR aquafuge. What do you think i should put in it?

 

If you can mix the sand that way there wont be a shift in bacteria IMO. I would place aragonite sand in the fuge.

 

What i have now is 40lbs of live sand and i'm prob gonna add 20lbs more. Should i use live sand again or other? Oh and i should have mentioned that the tank is only about a little over 2 months old. So should i still mix the two sands?

 

I would. but since you are doing a small upgrade i wouldnt put new sand in unless you like a dsb in your dt. I would use it in the fuge for the dsb.

 

IMO, I would use all new sand and just use a good scoop of the old sand to seed the new.

Or, you could get a good scoop out of the old sand, put it in the tank with the new extra sand, and then rinse out the old sand with r/o saltwater. If you do this you be sure to rinse the old sand very very thoroughly by stirring the sand in a large bucket or something. Dump the now dirty water, add new water, and stir, dump and repeat until the water is clear after stirring. This may be more hassle then it's worth. Also, Im not sure if you could get away with using r/o freshwater to rinse the sand. This may cause too much die off. Bottom line, when in doubt, go with all new sand and seed with the old.
As far as the fugue goes, think about some, chaeto or mangroves or lots of live rock. Also, try to keep the flow low through there. I have a deep sand bed in mine and things are fine, but my next project will not have one.
Hope this helps, and congrats on the up grade.