Hi--quick question wanted to run it by all of you. When I started my 29 gallon reef tank I did it per the suggestions of GARG (GARF.ORG) with the aragnite rock and the GARF grunge--and periodically I added more grunge--the problem is now I have a 4-5 inch substrate--I fear taking some of this grunge out as the system is seemily thriving and anything I would take out would more than likely be the most beneficial stuff on the top layer--has anyone encountered this same problem? cam you fathom any problems with keeping it at this level?