Bottom drilled overflow suggestions

[JDJP]

So i decided to replace my redsea max 250. And i found a BEAST of a tank to replace it.

Its a 36x24x24 made from 3/4" starphire on on all sides. The guy said he was making a 600gal and one of the sides had a chip so he built this tank for fun.

My plan right now is to make it a peninsula tank.
What would some of you suggest for an overflow? Kits? Diy? Ive been searching, but any help would be appreciated.

 

[JDJP]

 

[siliconinja]

That's a sweet tank! I'd love to know how you plumb this. I have a 75g that has 2 bottom holes drilled just like this.

I'd love to remove the overflow box, then the tank would look very similar to what you have.

 

[Smo]

Looks like the existing holes will drive you towards a custom corner drain. I would drill (grind) at least two more holes for a BeanAnimal drain system. Add an additional return if one wasn't enough.

Build a custom overflow box out of black acrylic. Glue strips of glass up the side and back of the tank to hold the overflow in place. Silicone cement works well on glass but not acrylic. Be sure you have sufficient overflow linear length for the planned flow rate. Longer is better.

Fun project!

 

[JDJP]

I have drilled a couple holes in some breeder tanks, but i dont think i want to mess with drilling holes in this tank. Although not completely out of the question.

 

[beaslbob]

I would stop on at you local home improvement store and look at pvc parts. To design my own overflow/return.

my .02

 

[JDJP]

Am thinking about running pvc up to an overflow box like this one

 

[beaslbob]

That would show the pvc going up to the box.

You might consider a couple of glass panels from bottom to top to enclose that corner. Local glass shop could construct. and you may have to have "teeth" at the top or some eggcrate.

 

[Smo]

If you have successfully drilled 40 gallon breeder tanks...this tank with its thicker glass will be easier. Just go slow and drill from the inside out so you have a clean chip free surface on the inside for the bulkhead gasket to seal well. Use a plywood jig to hold the hole saw steady as you start grinding. You could also clamp a sacrificial piece of (non-tempered) glass on the backside of the cut as additional risk reduction to chipping.

It's really not difficult to build your own overflow out of acrylic similar to the commercial one above. Simple jigs and basic tools are all you need. I would use their basic concept to maximize the linear drain length and then fabricate a smaller rectangular shaft (in cross-section) that led to the drains. That way you don't have to fill the entire end of the aquarium with an overflow box. Your rock-scape could cover most of this or you could glue on some birds nest coral frags and let them spread out over the drain box obscuring most of it.

But I am an engineer and tend to overthink things. Again--this project would really excite me!

 

[JDJP]

Ok i bought some 1/4" black acrylic and im going to make a 6x6x6 box to fit in the corner. Ill dremmel out some slots .
Im going to put a slip to slip bulkhead in the bottom and run the drain up to it and put a durso inside of it.

Yes you will be able to see the drain and return pipes, but i bought some black pvc and don't really think it will bother me. I also ordered some branch rock that may work to somewhat hide it.

This will keep me from having to drill new holes in the tank and I think i will prefer it to a black box taking up the whole corner.

 

[v10king]

Awesome looking tank!!! I am jealous, unfortunately I won't be purchasing anything like this in the future. Keep up with the updates please!

 

[Smo]

So it looks like your actual tank water volume will be about 75 gallons not accounting for rocks and sand, which would displace 3-5 gallons. If you plan for a 700 GPH return pump, ideally you will want 11" of linear overflow. Be sure you can accommodate that in your box design. Running 700 GPH thru a Durso may be a little noisy. But have fun and experiment.

 

[JDJP]

Isnt a 36x24x24 closer to 90gal? am planning to put a danner 950 gph which should be around 685 with head loss. And ill put a gate valve on the return to adjust flow.

Does the return need to turn over 10x if you have plenty of flow in the tank?

 

[Smo]

I used 231 cubic inches per gallon, accounted for your 3/4 in glass and about 1 1/2 in from the top edge. Old school suggests 10 x turnover but 5-6 is plenty good enough with a couple of power heads also in the DT (total of up to 40 x). Contact time is an important consideration in the sump especially if you also have a refugium.

 

[JDJP]

Had a friend come over and help me put the tank on the stand. I made a 6x6 overflow box the other day out of acrylic. Need to make a hole in the bottom for the bulkhead and cut some goles for water to flow through.

 

[Smo]

OK. I am jealous! Looking good.

 

[JDJP]

Thanks. First stand ive made. I think i need to put a couple more 2x4s somewhere to sure it up.

Im thinking of going no teeth on the overflow. Maybe cut some long ovals and silicone some clear net to the inside to keep fish out?

What do you think?

 

[JDJP]

 

[Smo]

A "zero edge" overflow works well in a "coast-to-coast" style overflow as it efficiently skims the surface water. In your case with what appears to be a somewhat small overflow box I would be concerned with a significant amount of flow over a relatively short linear distance. This may result in objectionable noise and possibly make it difficult to keep your CUC, etc., from slipping over the edge. Installing some type of screen that does not clog and at the same time keeps critters from going over the edge may be a challenge. I have seen folks make use of cutter guard in similar situations, but again, this may be too restrictive and contribute to additional noise. Is there any way to increase the surface area of the box?

 

[JDJP]

Yes, i could make the box longer if i bought more acrylic. But i was trying to save money and keep it smaller.
Worst case i can try this one and it would be easy to replace it down the road.