Quieter-Pumps will be behind a wall instead of under the tank. You can add sound deadening board/material between the rooms
Easier to scape - you only have one viewing pane instead of 2. So twice the trouble making it look good
Easier to plumb-Much more room to spread out the plumbing. Instead of cramming everything under the small space under the tank, you have pretty much the whole room behind the tank in an in wall. This is a most definite plus due to the fact that most of us are not plumbers.
Easier water changes-A big tank usually gets big water changes...weekly or biweekly. So a rolling tub would be used to bring water to the tank. The fish store I worked at used one for water changes. In a split moment of daydreaming, I pushed it instead of pulled it and in an instant there was 55 gallons of water on the floor. This could easily happen in a house. And would be an absolute disaster. In an in wall, you can just leave the tub mixing right at the back of the tank. (I guess you could do this with a room divider, but there would be hoses to deal with. Not that big of deal I guess, just one more thing to deal with)
Easier to set up lighting - You can more easily simply hang the lighting from the ceiling or hook on to the back of the wall and go over the tank with L brackets. In an in wall, you have to be much more careful and you would want it to look perfect because its out in the open, not hidden behind a wall. You could put it in the canopy, but on a 400 gallon tank, you wouldn't want to have a canopy on it anyway due to retaining heat...You could do fans, but those aren't silent either. And then your making it even louder than it is with just the pumps.
Easier to deal with humidity - instead of putting the humidity into your whole house, its just in one room. A small humidifier or small vent fan will be all you need to save you house from a mold attack. And save you furnace from taking on all that humidity. In a between wall, you could put a big vent above the tank, but there you go again adding more noise to the main living space. And how would you get the humidity out of the stand without a fan blowing thru it? Also adding more noise, and another electrical component.
Flooding issues - Small drips will be noticed in an inwall before a room divider. Believe me, you will be in that room behind the tank much more than under you tank. And you will spot even the smallest drip very easily. Therefore catch it way before any damage can be done. In a between wall, the plumbing is so tight together, you can't see everything easily and will be difficult to spot a leak unless there's a puddle or stream on the floor outside the stand. May be too late to save the floor at that time. Then you have to drain the tank, find friends to hold your livestock, move the tank, redo the floor, reset up the tank and hope your friends didn't kill the livestock.
I actually just overflowed my mixing bin yesterday. Was sitting there right before church started last night and it hit me that I forgot to turn off my RO unit and the bin was just about full a few hours before. Had a slight panic attack and almost got up and walked out, but realized that it didn't matter at all because it was on a slab. No worries.
Structure worries - I've been told that concrete for a crawl space is a cheaper mix because there will be no walls on it. (like I said, this is what Ive been told. Hard to believe, but makes sense. My garage is floor is fine, but my crawl space floor has cracks all over the place) Footers are placed only where there are load bearing walls carried down to it. So where your planning on placing the jacks, it could be a cheap concrete not meant to withstand that much direct pressure. I'd be VERY nervous placing that much weight on a crawl space floor from what Ive seen. If your not sure what footer is, just google it and what I said will make sense.
And just so you know I'm not talking out of my rear end here, I dealt with all these. The noise, the flooding, the structure, the plumbing on small and monster tanks. Inwalls and room dividers. Room dividers are simply more difficult to do it right. If you've had both, you can't argue with that. Don't get me wrong room dividers are cool, and I've seen some pretty awesome builds here that ended up absolutely amazing, but they are more difficult.
