Disturbing sandbed in a 2+ year old tank

[JCareyETexas]

Been thinking about rearranging some of my rockwork and even adding to it. My sand bed is 3-4" deep in various parts of my tank. When initially set up all rocks were placed first as to sit on the bottom.
Question is: is there anything to be aware/cautious of if I decide to uproot and rearrange my rockwork?

For those that are curious: I will be adding some nice ceramic pieces from vidarock to add depth to my aquascaping.

[thegrun]

I would have premixed saltwater on hand and a siphon hose ready to suck out as much detritus as possible once you start moving rocks. Depending upon how much junk gets disturbed, be ready to make a fairly large water change. Running a filter sock afterwards and carbon would also be a good idea if you are not already doing so. Unless the sand bed is filthy you shouldn’t have any major problems.

[pkirby]

I agree completely with thegrun. I'd definitely run a filter sock and carbon and be prepared to replace the filter sock as it may clog quicker than normal. I'd also be sure to do a large water change and would probably pre-mix additional water in case another water change is needed in a day or two.

[Hzuiel]

I would also do it over time in phases. I've heard of moving rocks releasing trapped gasses and sand releasing silicates. It could shock the livestock pretty bad if you stir up the entire tank.

[JCareyETexas]

Originally Posted by Hzuiel

I would also do it over time in phases. I've heard of moving rocks releasing trapped gasses and sand releasing silicates. It could shock the livestock pretty bad if you stir up the entire tank.

That's a good idea. Perhaps I will start this afternoon with some of the smaller rocks. Maybe move bigger ones the morning of a water change.

[bundybass]

I would definitely only do one small section of the tank at a time. If you have never cleaned your sand bed and I don't even recommend trying that, then there will be all kinds of things trapped in that sand that you do not want to stir up. So do small section at a time and be very careful not to still up any more sand than absolutely necessary followed by large water change and be sure to test water both before and after and watch for any changes. If you see a big swing then hold off on doing any other sections until parameters come back down to normal. If you see huge swings then do smaller sections!

[JDMR2]

I would think it's okay if you stir up a little bit so long as its only the very top layer. I'm not saying to go stirring it up at once. Still take care and do it a little bit at a time watching parameters closely. It's when you stir up the lower part of a deep sand bed where things get bad isn't it? Small critters living on the top layer keep your top layer stirred up anyway releasing trapped nitrogen gas pockets. That's the whole point of keeping beneficial sand bed critters correct?

[JDMR2]

Oh wait, just re-read the original post and the rocks are at the bottom.