Moving Rock Questions.

tank has been up for 4 months and I have decided that I want to change things up a little. Tank is a 57 gallon with the overflow box in the middle of the tank. I currently have the rocks stacked in the middle of the tank which still leaves room up front but there is still quite a bit of room on the back side that I dont get to enjoy from the front.
I set it up this way to make sure water could flow all the way around my rock but is it that important ?
I would like to set up my rock towards the back even up against the overflow.. is that an issue? The overflow box has 3 sets of slits for water to go through and I think that as long as its not blocked water will still flow through, but will it impede getting suspended debris in the water column out of the dt and into the sump?
I have been looking for as much info as I can before I move everything, Im upgrading my sump here in a month so I was planning on doing this at the same time..thanks for any imput.

 

Hide a small powerhead behind the rocks or if you have a nice wave maker I don't see it being a problem at all.

 

Stacking the rock against the back is actually fairly common- don't have much choice if you want room in front in a standard rectangle. A powerhead or two deflecting off the front glass back onto the rocks will provide plenty of flow through the structure.

 

Try to make sure your rocks are cleaned up ahead of time before moving them so you don't cause a mini cycle. Cleaning rocks has always been part of weekly maintenance for me. I try to leave large holes between rocks for fish to swim through & it keeps water flowing through also.