Need input before i drill holes

[mikesuperrc]

Hi.
I'm looking for some advice on my overflow set up before I drill holes.
I'm setting it up as a ghost overflow style weir and BeAnAnimal drains.

Mainly I'm wondering if these holes are low enough and if I have enough holes connecting the inside box to the outside box.
I am probably going to spread the connecting holes further apart, most likely evenly spaced along the box, I didn't think of doing this until after I finished the drawing.

Also, the hight of the wier in relation to the holes and the top of the tank, is 25mm from the bottom of the euro brace enough or too much? the euro brace will be 20mm thick.

One other thing, teeth or no teeth on the wier?

Anything else I have overlooked?

Thanks,
Mike

 

[laverda]

I would not use teeth my self. You will get a nice thin sheet of water flowing over it. The height depends on several factors. Will you be using a canopy? If so you probably want the water level above the bottom edge of your canopy. The biggest factor is how much flow your return pump is going to bet putting into the display. If you have teeth or not is another factor. There are formulas that will calculate the height based on flow. https://www.engineeringtoolbox.com/weirs-flow-rate-d_592.html.

 

[mikesuperrc]

Hey.
Ok no teeth sounds good them. I want it as quite as possible.
The pump i have is a dc one with speed control id have to double check but i think it can do 2000lph or something. I haven't looked at it in a while so i may be way off.
Tank was a 4x2x2 but i have cut it down to a bit over 3x2x2 as one end was damaged and i wanted a bit smaller tank. So the pump was used in a bigger tank originaly.

I tried to use the calculator you linked but i cant get my head around the right parameters to put in. Are you able to provide a bit of insite. eg. how do i find what my weir height is as where is this measured. Amd what units and how do i ftried ure out the constant discharge. Is this the target flow rate?

 

[lapin]

To help on weir flow, I would look at overflows that are sold and find one that is about the size of yours.
https://synergyreef.com/product/16-shadow-overflow/
The amount the weir will flow depends on how high a water sheet you push over the top of it. More water = thicker sheet. More water also = more noise. For most boxes the flow is restricted by the size of the bulkhead you use for your main drain. If that drain will not handle the flow from the pump then the weir and tank will overflow.
No teeth is the best. However you will have a good chance of critters going over the falls.
Height; I push about 10mm over my weir. My weir is about 40mm below the top of my tank. This leaves an air gap between the top of the tank and my tanks water level. Maybe more than some people would like. I could push more water over the weir causing the tank level to rise a bit more. I have an in wall tank with a frame around the opening. Water level in the tank was not a concern as it is covered by the frame.

 

[mikesuperrc]

Ok. So i might want to lower the holes joining the boxes and lower the weir. 25mm might be a bit tight.
I am going to make the ext box deeper as a friend said they wish there's was deeper.
All the bulkheads are 25mm/1".
Would i benifit from adding a 4th hole joining the boxs do you think.

I did consider are reef synergy or saavy reef etc but none where big enough with out getting it custom ordered.