Acroholic;943498 wrote: I asked this same question before I turned my 300 bare bottom (before going to the 465), thinking what you posted here, and I was told there is very little buffering from a sand substrate. This makes sense after it was explained to me, because to dissolve aragonite media in a calcium reactor you need a low pH, much lower than you'd ever have in the water column of a reef tank. Regular substrate will not dissolve at normal tank pH levels.
Now what you will probably find with a BB tank vs one with a substrate is a higher overall ORP level in a BB tank. That is what happened to mine when I pulled the substrate out of my 300 gallon, back when I actually cared what my ORP level was. My average ORP went up by 100, from 250 to 350. That tells me my substrate was holding a lot of organics.
