Downsizing, need opinions

[Aquattro]

Originally Posted by fishoholic

Use the top layers of sand (the LR of course) and I would use only half of the old water since once you stir up the sand gunk will be released into the old water.

not if you siphon out the water first

I would expect to require a good water change a few days after the move, but that's what I did moving from a 150 to a 75. Depending on how much rock you have, you may want to use only half. I had about 200 pounds or more in my 150, and only used about 65 in the smaller tank.

[Biotech]

Thanks everyone
Based on all the advices provided, I think I will put in new sands as I am not thinking of a deep sand bed and will only transfer ~1.5lb/gal of LR into the new tank. Will initially completely fill the new tank up with old water (and will be careful not to disturb the old sand bed), and then do a 25% water change after 2 weeks.