Built-on Overflows

[GLD]

Is it possible to purchase a tank that has overflows built onto its back?

If not, is it possible to cut slots in the back glass pane of an aquarium and then build an overflow onto the back of the tank by attaching glass or acrylic onto the backside of that pane?

Obviously, I am nervous about relying on siphon-driven overflows, but don't want to buy a reef-ready tank that has some of its interior lost to internal overflows.

I look forward to all ideas, guffaws, etc.

 

[Reefguide]

Interesting, I think it might hold back the water pressure, you would need to seriously strengthen the tank at the top and bottom with a few braces from front to back at each end of the overflow box.

 

[K77]

Is it possible to purchase a tank that has overflows built onto its back?

If not, is it possible to cut slots in the back glass pane of an aquarium and then build an overflow onto the back of the tank by attaching glass or acrylic onto the backside of that pane?

Obviously, I am nervous about relying on siphon-driven overflows, but don't want to buy a reef-ready tank that has some of its interior lost to internal overflows.

I look forward to all ideas, guffaws, etc.

Interesting idea. It would have to be custom made though, and anyone who would be brave enough to make it for you would probably charge a pretty good amount for it.

Have you thought about customizing your overflows a little? Maybe make the drains/returns about 1 &1/2" and then do corner overflows on the back that come out less than 2" from the back and are longer. It might give you more usable space that way if that's what you're looking for.

Overall though, an overflow is not wasted space. The best use of them is to put a durso standpipe in them and use both as a fuge. It works great, its hidden, and it increases your water volume (the more the better).

 

[reefland]

Sanjay Josi used a sandblaster to cut the overflow slot into the back of his tank which has another smaller tank attached to act like an overflow.

From Sanjay's Webiste:

The tank has two slots 10" long and 1" high cut into the back of tank. These slots were cut by sand blasting which I had done at a local store that specializes in making tombstones and headstones for graves. They have the best sandblasting equipment since they use it for sand blasting the designs on the granite used for the tombstones.

and

Attached to the back of the tank on the outside is a 36"X8"X10" add on tank

The bottom of this add on tank has a sand blasted hole for a 2" bulk head fitting, and is the main water return to the sump.

The side of the this add on tank also has a 3/4" bulk head fitting which feeds the water to the skimmer, so I don't need an additional pump for the skimmer, and I am able to directly feed the surface skimmed water into the skimmer.

Inside the tank, is attached a 36"X2"X2" box, which acts as the surface skimmer.

 

[ChrisRD]

GLD:

Another option you might be interested in, although not totally external.

On a 50 gallon tank I just setup recently, I had the tank drilled for a bulkhead on the top center of the back glass, just as you would if you were going to use a regular strainer intake. I didn't want the noise associated with the strainer intake, so I did something a little different.

I constructed a very small overflow box out of acrylic. I screwed a threaded 90 degree PVC elbow into the bulkead inside the tank pointing downward. I then siliconed the overflow box inside the tank over the elbow. I plumbed this line, externally, like Rich's standpipes.

This is basically another rendition of Rich's design, but with all the plumbing outside the tank. The only thing inside the tank is the small downspout, and a tiny overflow box. This box only takes up about as much space as a hang-on overflow box would - very little tank volume is lost.

I can try to post a pic from home tonight if you're interested.

 

[reefland]

Wolfman:

Kinda like this? But instead of being attached to an external box. The bulkhead was connected directly to the tank and then you have a box on the inside to keep critters out.

 

[ChrisRD]

Exactly. Works like a charm.

 

[Jeff Hood]

Its easy to have them attached if your tank is Acrylic.

Here are mine. They work great!

 

[ChrisRD]

Jeff:

How much noise do those things make? Looks like there's a fair bit of drop for the water coming over the edge. I suppose being it's mounted in the wall it wouldn't be much of an issue anyway, but I was just curious...

 

[Jeff Hood]

In the house they are silent. In the fish room it is a ROAR. What you see is only one pump on for testing. I run two ampmasters through the tank for sump circ.

I did raise up the water level to see what happens and the noise almost went away. you could also run a stand pipe of the various designs and that would work well.

I don't mind the noise in the fish room so I keep the level low.

 

[reefland]

Jeff - That's a nice looking setup.

 

[fishfarmer]

I made corner overflows for my 55 gal. I had two holes drilled in the back in both corners. I made two skimmer boxes out of acrylic. They are inside the tank but in each corner. Two piece construction, a front and a triangular bottom piece. They are only about 4" deep and have enough space for the bulkhead strainer to fit inside the box.

 

[Marcosreef]

Jeff,

Real nice. Did you have it made or did you DIY?

Marco

 

[GLD]

Thanks for all of the responses. I can understand the ease of attaching an acrylic box to back on acrylic tank, but what would you do with a glass tank?

Wolfman, I would love to see pictures of your device. Thanks.

 

[ChrisRD]

GLD:

I posted a pic in one of my earlier replies. Try hitting reload - maybe it wasn't working for you. If you can't see it in the thread, email me and I'll send you some pictures.

Jeff:

Thanks for the response. Very impressive setup.

 

[Jeff Hood]

Marcosreef


The tank was made by Tencor.

I got the Idea from a couple of reefers on the various boards. I love the external overflows.

Easy to maintance if you have access from behind.

Jeff

 

[jandree22]

I constructed a very small overflow box out of acrylic. I screwed a threaded 90 degree PVC elbow into the bulkead inside the tank pointing downward. I then siliconed the overflow box inside the tank over the elbow. I plumbed this line, externally, like Rich's standpipes.

So has the silicone bond between the glass tank and acrylic overflow box held?

 

[Anonymous]

completely doable.

I use a tile-cutting bit on my rotozip. Others have used a dremmel and a diamond bit.

this is my 20 gallon. The back acrylic teeth were cut with a lazer cutter. On my current tank (58) I just used a router.

Search "external Overflow"

B

 

[Anonymous]

Here's a pic of my 58 gallon. The acrylic is 3/16 or 1/4" I can't remember right now

 

[ChrisRD]

I constructed a very small overflow box out of acrylic. I screwed a threaded 90 degree PVC elbow into the bulkead inside the tank pointing downward. I then siliconed the overflow box inside the tank over the elbow. I plumbed this line, externally, like Rich's standpipes.

So has the silicone bond between the glass tank and acrylic overflow box held?

It held fine for several years until the tank came down.