Fluval Breeding Box HOB Overflow DIY

[seanarino]

I had originally bought this Fluval Breeding Box that hangs over the back for a small cheap "HOB Refugium", but removed it when I had to upgrade my 10 to a 20g on a short notice (tank cracked). I'm wondering, theoretically, if anybody has any ideas on how I would be able to turn this into a HOB overflow somehow. I plan on really only using the box itself and not the pipe on the right of the image or the barriers on the inside. Instead, I was thinking of turning the "out flow" part into where the u-tube sits, and attaching an overflow box that goes inside the tank (the part with the weir). I'm not too sure how well this would work, so I also added some images of it sitting on a generic-sized ruled notebook for scale (ft. Beans the cat).

I'm trying to brainstorm some possible ideas because I think modifying an existing box would work better for me than attempting to build a box out of acrylic. This is *much less likely* to fail in a way that would cause serious issues.

 

[Peace River]

IME, the challenges with HOB overflows are keeping it primed and keeping it from overflowing.

You may find some inspiration in this video:

Good luck with whatever direction you choose!

 

[seanarino]

IME, the challenges with HOB overflows are keeping it primed and keeping it from overflowing.

You may find some inspiration in this video:

Good luck with whatever direction you choose!

Yeah it's unfortunate that I can only do HOB - I can't drill my tank - plus it's already got water and everything in it!

 

[Peace River]

Buying a commercial HOB overflow is obviously more expensive, but they have worked through many of the issues related to priming and overflowing. Having built a DIY overflow in the past and also having a commercial overflow, the one I built was far more finicky. One thing that I discovered with the priming issue what that if I used a micro pump to continually feed water into the overflow tube it really helped with not losing the syphon.

 

[seanarino]

Buying a commercial HOB overflow is obviously more expensive, but they have worked through many of the issues related to priming and overflowing. Having built a DIY overflow in the past and also having a commercial overflow, the one I built was far more finicky. One thing that I discovered with the priming issue what that if I used a micro pump to continually feed water into the overflow tube it really helped with not losing the syphon.

Oh? A micro pump?

 

[Peace River]

I don’t remember what brand of micro pump that I used but it was in the 50 to 80 GPH range. You should be able to find some thing similar by searching for a mini fountain pump. This approach pumps a small bit of water from the tank into the overflow syphon tube to keep it going and clear out the air through added flow. Another approach would be to look at a Tom’s aqua lifter pump, which can pump both air and water and it’s usually configured to remove any air that builds up in the overflow tube.

 

[seanarino]

I don’t remember what brand of micro pump that I used but it was in the 50 to 80 GPH range. You should be able to find some thing similar by searching for a mini fountain pump. This approach pumps a small bit of water from the tank into the overflow syphon tube to keep it going and clear out the air through added flow. Another approach would be to look at a Tom’s aqua lifter pump, which can pump both air and water and it’s usually configured to remove any air that builds up in the overflow tube.

I'll check that out! I know there are a lot of really tiny pumps, so I'm sure there's one that's gonna be good enough to pump enough for a small overflow. My only issue was that I wanted to do a bean animal-type overflow because I'm paranoid of failure points, and the commercial HOBs tend to be "one pipe" only. Do you think I should just go with a well protected one-pipe or attempt to modify this for a bean animal?

 

[Peace River]

A being animal typically has three holes, where, as a Herbie typically has two (which is what I used with my overflow box). There are users here on this forum that swear by their HOB overflow and claim to have never had an issue. That is not my experience. Please understand that I have built a DIY overflow and used commercial overflows (and am sharing where the likely failure points and some solutions that worked for me), but I have moved away from them with all of my tanks. It is very possible to build a DIY overflow box, but I would be prepared for plenty of tweaking and be prepared in case something goes wrong.

 

[seanarino]

A being animal typically has three holes, where, as a Herbie typically has two (which is what I used with my overflow box). There are users here on this forum that swear by their HOB overflow and claim to have never had an issue. That is not my experience. Please understand that I have built a DIY overflow and used commercial overflows (and am sharing where the likely failure points and some solutions that worked for me), but I have moved away from them with all of my tanks. It is very possible to build a DIY overflow box, but I would be prepared for plenty of tweaking and be prepared in case something goes wrong.

I think I'll check out some of the commercial HOB overflows, then - I was just nervous at first because of flooding!