how about using the 10g as a sump and leaving the sand bed as is... thats what i plan to do when i upgrade my 20g to a 33g

I think im going to use the 10 gallon as a hospital/quarintine/frag tank. I just built a stand so i can hide it benieth my 20g. I guess i'll just leave the sand in there, maybe seed a little into the 20 after i wash it.

When I swapped my 180's, I shoveled (literally with a dust pan) all my sand into pails, did a quick rinse with tank water, then dumped it into the new 180G.

I saved all the old water I could, and put what wasn't in drums holding my rock back into the tank and ran a diatom filter on it for 2 days, stirring it a couple times a day, and changing the bed in the diatom at times every couple of hours when it plugged.

I have not seen any issues in my tank since everything was put back in.

HTH