Bottom sweeping overflow

[Mardisump]

Hello folks,

I'm planning a new tank with a bean animal overflow system on the shorter side. I'd like to redesign the interal weir overflow box so that it would be able to sweep from a lower area and skimming from the surface as well. The top of the internal box is partially open between the reinforcements to allow an emergency overflow option in case the slits get clogged.

The internal box is placed 20mm (0.8") below the edge of the aquarium and the bottom of the upper slits are another 25mm (1") lower. We can count with an additional 5mm (0.2") rise of water within the slits due to surface tension, so the water level would be approx. 30mm (1.2") below the edge of the tank.

I might need to reduce the lenght of the slits on the top to allow more suction through the lower ones.

Do you think this "bottom sweeper" internal box could work properly?
Thinking about maintenance, possible dead spots inside, proper flow rate, the ability to remove debris from the tank, retaining skimming ability despite of the lower flow rate at the top slits, security, etc.

To my knowledge, as it is an open channel, it can't produce a full syphon, thus it won't be able to accidentally drain the tank down to the lower slits of the internal box. Right?

Front glass is hidden for better visibility and water level would be where it is shown here.

Frontal view:

Side and back views:

As I understand correctly with this model, in case of a power failure the water level of the display tank would drop to the lower edge of the drilled holes leading outside of the tank to the external overflow box, right? That's 100mm (4") below the edge of the tank. So I'd need an appropriately sized sump with a puffer capacity that easily holds that extra volume (72 lt = 16 gal). That sounds ridiculous. Shall I rather raise these holes a bit higher up to reduce this large volume? If they are too close to the top, then they could add extra noise when water flows out to the external box. So we'd need to make a compromise here.

Another option to add an extra level of safety could be with the addition of a typical smaller volume internal overflow box (think about the Marine Systems' 20") placed behind the "bottom sweeper chamber". In that case, the water would only drain to the bottom of the skimming slits of the smaller chamber. The only issue with this double chamber solution is its size, especially the width. Would take double the space from the display area than this simplier version here.

What do you think?

 

[blaxsun]

I think it could work, yes. Maybe look at Cade's overflow design - they have a weird top and bottom.

 

[Mardisump]

I think it could work, yes. Maybe look at Cade's overflow design - they have a weird top and bottom.

Thanks. Are you referring to this?

How does the weir’s low-level intake work in the event of a power outage or when the pump is off?​

Behind the low intake vents is a sealed glass channel that diverts water to the surface. This glass channels function is to both direct the debris to the surface for direct intake to the surface level plumbing and also to prevent water flooding the weir when the pump is switched off.

Sounds like it's the same design as mine.

 

[All_talk]

I think the Aqueon reef ready overflows have always had this feature.

 

[blaxsun]

Thanks. Are you referring to this?

Yea. And sorry, I meant "weir" top and bottom (not weird).

 

[Mardisump]

I think the Aqueon reef ready overflows have always had this feature.

Is that a thin, sealed chamber where the slits open to and its wall is slightly shorter than that in the front?

Yea. And sorry, I meant "weir" top and bottom (not weird).

Haha, maybe their weirdness lies within their hypermaximalism Wondering how much such a system could cost.

 

[EeyoreIsMySpiritAnimal]

Is that a thin, sealed chamber where the slits open to and its wall is slightly shorter than that in the front?




Haha, maybe their weirdness lies within their hypermaximalism Wondering how much such a system could cost.

This is the Mega-flow overflow box. It's basically a double walled overflow box - the inside wall is slightly taller than the bottom of the weir on the outer wall. The water that's pulled in from the middle and lower slits goes up between the walls and over the inside wall to the overflow area. I have this overflow on my current tank and like it, but it does not take long for the space between the walls to become it's own ecosystem, lol. Lots of stuff growing in there.

I wish someone made these large enough for 3 bulkheads. The AGA/Aqueon Megaflows only have room for 2... I run my return up over the back of the tank so I can run a Herbie.

 

[Mardisump]

This is the Mega-flow overflow box. It's basically a double walled overflow box - the inside wall is slightly taller than the bottom of the weir on the outer wall. The water that's pulled in from the middle and lower slits goes up between the walls and over the inside wall to the overflow area. I have this overflow on my current tank and like it, but it does not take long for the space between the walls to become it's own ecosystem, lol. Lots of stuff growing in there.

I wish someone made these large enough for 3 bulkheads. The AGA/Aqueon Megaflows only have room for 2... I run my return up over the back of the tank so I can run a Herbie.

Anything can be made out of glass or acrylic, so it really depends on the design process you want to invest. Despite that, I'd certainly buy an out-of-the-box solution if there was any in my country.