Switching sand beds?!

[Demogarr]

My plenum system has been breached all the way by an unidentified three foot worm! I will have to break it down to repair it, and while I have it down I am thinking about going with a deep sand bed. I am going to have to get different grained sand, which means new sand. How do I need to go about this?? I am going to be losing lots of biological filter. Some of my existing sand may be fine enough to put in with the new sand, but most is too course. I can trap a few hundred of the bristle worms and flatworms already multiplying in my system easy enough. Should I get all the new sand in some containers and let it age in old tank water for a couple of weeks to let it get a good bacterial coating before adding it to the tank?? I think I read that somewhere. Just needing some opinions here.. I also put my biowheels back on the penguin filter to get some bacteria going again to ease the transition whatever I do. Thanks in advance!

[Spanky]

I think I would just take it out and replace it in small sections, a little bit at a time. Are you able to actually cut your plenum? like egg crate? I read something, somewhere about migration of sand critters from old to new areas. I remember it took a lot longer than I though it would. So give it some time.
I really don't think you need to run the biowheels and I would worry more about them and nitrates.

I've never done this. Just guessing.
HTH
Jerel

[Demogarr]

I do have eggcrate, so I could cut it, but I can't figure out how to just do it a little at a time without mixing all the course sand of the plenum with the finer grains I will be putting in, maybe screen or something? I can't really even get the eggcrate out without taking out everything and just pulling out all the sand. I guess I will let the new sand sit in some tubs I got in old tank water with a powerhead for a couple of weeks. Then I will switch the beds, hopefully there will be some bacteria built up. I will also trap as many sand critters as I can from the old sand, including the 3 foot worm( don't want to lose him!) I will then get a detritivore kit to further seed the sand. I will be testing the water quality all the time to catch a nutrient spike before damage is done, if there is a spike, my lfs will be able to hold my most of my corals and definately my fish(great guy) Hopefully it will not come to that. Something must be done however as the plenum space beneath has been totally breeched and sand is falling under the eggcrate more and more each day.

[Minnreefer]

I am no means even close to an expert but I do have one idea... I like your idea of letting the new sand settle for a while before adding it to your tank, how about adding some of you current sand to help the proces.
Jon

[Demogarr]

Just wanted to clarify that I am taking the whole plenum system out and getting finer grained sand to use in a lagoonal style deep sand bed. Anyone know where ot get some good prices on sand in Arkansas. Home Depot will only order the southdown if I get a whole pallet, and I do not need that much sand! (not yet anyway )