Hang in Back Overflow Pictures (HIBO)

(HIBO)- Hang IN Back Overflow

I found an interesting Tank mod when I was surfing the internet looking for ideas when setting up my 55 Gallon flat back hex... [fig1] This design used an external overflow that did not require the dreaded siphon tube or other method to keep the flow primed... which have been known to lose prime and cause floods... the HIBO is basically a “slot” cut into the back of the tank with four sided box attached to the back of the tank surrounding the slot to act as an external overflow which is fed by water flowing over the slot into the box. See drawings explainations Fig[10].  This way there is no real estate lost in the tank and no need for siphon. The HIBO  is easy to retrofit Acrylic Tanks because all the work is done EXTERNALLY. Glass tanks is another story however... :)

This can overflow can be protected with black eggcrate Fig[2-3] and also silenced with my CJStandPipes. Fig[4] Since this standpipe design is so narrow only 2.5” is needed for the HIBO box across the back. (fig1) the overflow box does not extend very far back off the tank so not much space is lost behind the tank either!  I decided on a four sided box fig[7] so the  area melted to the back of  tank would be larger and stronger than just melting the sides of the box to the tank. This method is also easier.... Just make sure the box is adheared tightly using clamps when gluing...fig[5a-b] pay close attention to the top of the box that is glued right below the slot.... so no water gets behind the box from the slot...fig[1

The tools used to cut the tank were a Rotozip Revolution with diamond blade fig[6] and a specially purchased plastic drill bit fig[8] from Plastic Store to drill pilot holes in the corner of the slot fig[9a-b]. Dont try this with a carbide drill bit no matter how good it is.. it will chip the acrylic. Pay the money and get a good one from your local plastic dealer.