DIY False Wall for All-in-on tank. What is the best approach and plumbing?

[ps2cho]

I am getting a 12x12x12 7.5g glass tank in the next few days and my plan for this tank is for coral quarantine, and an emergency tank.

I HATE surface skum with a passion, and I want to keep this tank as self contained as possible. So I thought about making a false wall and turning it into an AIO tank.
I figure the best bet is to use acrylic /w GE silicone (I used this method /w an overflow box).

What about compartments and the return? I have zero need for anything other than enough space for the heater and a return pump and enough space for a DIY ATO float valve since evaporation will be an important consideration...

1) How much space should I have? (no experience with AIOs)

2) Since its so small, how do you guys do the return line and how does it go through the false wall? Whats the best method/hardware/plumbing?

3) What return pump should I consider? I don't need much flow...but what would be considered normal for a 7.5gal tank?

 

[jservedio]

I personally would use glass since the tank is glass and it is really easy to work with when cutting straight lines and it bonds with silicone, instead of just being "wedged" in by it. To determine size, you need to "dry-fit" your return pump in, your heater, and any media that you want in there. Leave an extra 1/4" for some breathing room and there you go.

Since it is DIY, I would either leave it as a single large chamber, or make it a 2 chamber design so you can have a media rack directly after the overflow. I would measure the media rack and make the chamber the exact size of the media rack so you have no water flowing around it.

For the return, simply drill the false wall the same way you would for a regular tank. For a small tank I would use a 1/4" threaded sch-40 bulkhead, a 1/4" MPT to 1/4" Loc-Line adapter, and a single 1/4" fan nozzle (you can add more locline to aim it if you want, but it takes up space). Inside the false wall, a simple 1/4" elbow pointed down with a 1/4" hose barb on the bottom. Connect the return pump to the hose barb using 1/4" silicone tubing (super flexible and it makes removing it easy).

For return pump that is up to you. If you are going to have an additional powerhead, something as small as 75gph would be fine - but if that is going to be your primary water-move, you probably want around 200-250gph. I have 95gph in my 2g pico and it is the only water pump. Since it is not in a sump, you don't need to add any head height at all - the pump will operate at its true rating.

I would seriously consider copying an existing design for a similar sized AIO pico. It is VERY hard working in such small spaces and I would consider not building a false wall and using a HOB filter modified for surface skimming to handle the surface scum.

 

[ps2cho]

Nice reply awesome!

I have an MP10 for flow in the tank.
Would this be OK for the return then? Amazon.com: Rio Plus 90 Aqua Pump - 85 GPH: Pet Supplies
I considered the HOB idea -- I did it on my larger tank and I don't want to for space reasons. This tank fits perfectly in my stand for my 60g. I have no room for a HOB.

If I went with that return, I could get away with a 2.5/3" space which would give me enough to put any heater, the pump and the autotopoff nano (AutoTopoff.com)

I have attempted glass before. I am not sure if it was too thin, or my technique...but I scored it 10x then did a swift snap and it never snapped perfectly. It would end up making a curve at one end...

 

[jservedio]

Nice reply awesome!

I have an MP10 for flow in the tank.
Would this be OK for the return then? Amazon.com: Rio Plus 90 Aqua Pump - 85 GPH: Pet Supplies
I considered the HOB idea -- I did it on my larger tank and I don't want to for space reasons. This tank fits perfectly in my stand for my 60g. I have no room for a HOB.

If I went with that return, I could get away with a 2.5/3" space which would give me enough to put any heater, the pump and the autotopoff nano (AutoTopoff.com)

I have attempted glass before. I am not sure if it was too thin, or my technique...but I scored it 10x then did a swift snap and it never snapped perfectly. It would end up making a curve at one end...

When you cut glass, you should only be doing a single score, the wheel has to be lubricated and spinning freely, and the cutter has to be perfectly perpendicular to the glass. Also, you have to go fully from edge to edge otherwise you can be left with jegged, rough ends. Most people end up pressing way too hard and the wheel doesn't spin or it isn't held at exactly 90 degrees. If you score it over and over, there will be multiple places for the glass to break and you will get a nasty edge. Instead of looking at reefing resources for cutting glass, take a look at some of the stained glass forums or channels on youtube.

If you have an MP10, get a pump that matches how much flow you want through your "sump" in the back wall. I really like the Hydor pico evolution pumps because of how small they are. You could probably have it take up 2" or less with one of those.

Also, if it is just a pump, heater, and ATO, you probably only need a single chamber. With glass and such a low flow pump, you could have a coast-to-coast toothless overflow and you would be getting a super thin layer of surface water.

 

[ps2cho]

So basically the toothless coast to coast is just one single sheet of glass from wall to wall and the height of it a little less than the tank. At this point it will simply just flow right over?

Is making a hole in the glass for this tricky?