Can I change my sandbed, to southdown, without recycling. I was thinking about taking out the rock, critters, and water and just dumping the old sand and replacing it with southdown. Can this be done safely?
Fran - I'm not sure if you would experience a cycle or not. Maybe leave your critters in their holding tanks (whatever you plan to use) for a day to let the rock do its thing, and test the water. If you do experience one, it will likely be small, due to the live rock and water from the tank. I'd keep your rock in some water to prevent as much die off as you can. Before you put the rock back in the tank, give it a good blasting with a powerhead to free up any detritus/junk that has collected. Here is a thread where Chuck removed his sandbed - didn't replace with new, but you will get the idea. I would try and have several bins - one for live rock, corals, and critters....powerheads and heaters:
I didn't remove my sandbed but removed the crushed coral in the tank. I took everything out drained the tank and removed the crushed coral. The sand had made it's way to the bottom of the tank so I didn't have to take it our completely. But it was pretty dirty and the tank went through a mini cycle that lasted about three days then was back to normal.the scooter and the snails love the sandbed better than the crushed coral.
Nikki made a good point of blasting the rock before putting it back in. It's not ofetn that you get the chance to clean stuff off while doing some maintenance on your tank.