DIY Weir question

[neptunestender]

I am working on a diy weir and I would like some input on the slots at the top of the tankside box. I am working with 1/8" acrylic. what is a good spacing and depth of grooves? I know max depth of grooves would be to the depth the tank could drain durring a power outage, right? I wpuld like the water level as high as possible durring operation. the total length of the overflow including sides will be 24". box demensions are 16"/3"/6" deep. also would one blades width on a table saw be good or should I use a dado blade? any input here would be greatly appreciated.

Thanks in advance,

Ed

 

[kcress]

The general consensus around here is: Avoid teeth at all costs!

If the weir is reasonably long or the flow reasonably low the height of the water going over is scant. If you still have issues then add some "egg crate", which is that plastic square grid stuff on the top.

Either way the grids are way easier to deal with than teeth. (I know - I've spent hours with a Dremel Tool trying to 'adjust' teeth)

 

[NanoReefWanabe]

i completely agree with above...the teeth drastically reduce the linear length of the overflow...which in turn drastically reduces its capacity to skim the surface of the water...

 

[neptunestender]

sounds straight foward enough. I guess the rest is just math on flow rat and desired height of water. My only real problem will be this weir will be built in a rock wall and have no access to be removed or worked on so I better get it right the first time.

Thank you both for your input. The lack of teeth just made my job easy!

Ed

 

[kcress]

Yes the rock work is an adding issue. In my opinion no teeth even works better in that case.

The teeth actually cause the water height to dramatically change with flow as compared to no teeth. Also since the water passes thru just the tooth gaps the flow is greater at the teeth(naturally) but this forces the water off the wall to crash down into your overflow in tooth-spaced streams instead of a laminar flow down the inside face.

 

[neptunestender]

Just Finished w/pic

Just Finished w/pic

Just finished! I shall name her "Toothless", and she will be my friend.:beer:

 

[kcress]

Damn! That looks nice.

She will serve you well.

Thanks for the pics!

 

[bikeboss11]

It looks great buddy not sure I understand the concept all dat well... Isn't the eggcrate suppose to be facing vertical instead of horizontal?

 

[neptunestender]

I give up, is it? maybe kcress could weigh in on that if he stops back by. It is very posible I misconstrewed his original post. For the sake of simplicity I hope this one passes muster.

Ed

 

[jackde]

Looks great! Wish I'd have done mine toothless and in black or smoke.

 

[zeebies]

Very nice work, Neptunestender. Are the grids just wedged into place or are they sitting on a lip? I'm assuming there are are 2 grids?

 

[neptunestender]

they are setting on an 1/8" lip recessed so that the grids set flush and there are two grids because of the center brace. I made the back lip to slip between the glass and the plastic rim of the tank, and the center piece is to rest against the tanks center brace.

 

[kcress]

Well... Your work looks great. Really nice. I can't say I actually understand how you're applying those. I figured they plug into some structure?


Oh..

Vertical man, VERTICAL. Instead of teeth on your vertical weir you just build it with a straight edge. The water height will be just a little higher than the straight edge. Now IF you have a creature problem you can add that exact egg crate you have as an additional VERTICAL wall on top of the weir's edge.

That said, what you have horizontal may work fine. Give it a try. The only problem I see is that it might be noisier. Maybe not.

 

[neptunestender]

thanks for the input I'll try it this way and see if its too noisy I will try vertical. I am realy just a noob and did not understand the implied vertical in earlier post. oh well I think I will go ahead and engineer some vertical ones befor I install just in case.

 

[LoJack]

if one of your fish gets sucked over the wall like my clowns love to do ... won't he get crispy and dry out.

 

[neptunestender]

yeah kcress pointed out the eggcraye should go vertical. and I thought I did such a good job. will most likely go vert with eggcrate

 

[kcress]

LoJack; You make a VERY good point.

 

[neptunestender]

The new and hopefuly improved!

The new and hopefuly improved!

Well, I went vertical. So how bout now?

 

[iced98lx]

nice bending on the grid!!

 

[kcress]

Damn! The guy's an artisan..