DIY Corner Tank Build.... Need Suggestions.

[Verbalkint]

Ok.. My wife and I have wanted a corner tank for quite some time now..

The advantage I see a corner having over a wall is same amount of water, less space (not withstanding it sticking out into the room a bit fruther, but we can live with that).


I was thinking going DIY on this, mostly for the experience for future projects, etc.

Here's what I want... (pardon the ascii art, no gfx software here at work)

(Mind you, this is not scale)

         3'
  |------------|
  |               |  6"
  |              /
  |            /
3'|          /
  |        /
  |      /
  |---/
     6"

Appx 3' tall

Now, for some facts.

The 2 back sides (3' each) will be plywood / fiberglass
The bottom of the tank will be Plywood / fiberglass
The 'viewing' side will be acrylic.

Now, the questions.

1: How many gallons, appx, would this be? (My math sucks today)
2: What thickness plywood (I was thinking 2 layers of 1/2, overlapped, or 1 layer of 3/4 - 1")
3: What thickness would the acrylic need to be?

The reason for plywood on the back walls is simple. Strength / Price ratio and the fact that you wont be looking into the tank from that side (with it being against a wall, and all)
Plywood on the bottom, easy to drill for an overflow box.

I know the costly part is going to be the front acrylic, but having access to a cabinet building shop (run by a friend of the family), all the tools i'd ever need are available, as well as prolly 75% of the wood.

Many Thanks.


Dave

 

[austinsdad]

The calculator above can figure your gallons for you based on tank dimensions.

 

[Verbalkint]

I've seen those before, but they are for a regular tank, or a hexagonal tank.

A corner tank is basically a square cut in 1/2 from corner to opposite corner. Based on a 3' square tank, thats 201 gallons... By 1/2, appx 100 gallons..

Ok. (this is correct, yes?)

 

[Clown Monarch]

If you're planning on making it SW, I have three words of advice:

DON'T DO IT.

I have a 44 gallon pentagon (corner) tank that used to be freshwater, and I recently decided to go SW with it. Here are the problems I've dealt with:

1. Getting a significant amount of light in the tank is VERY difficult. With only about 20" at the tank's longest reach, no PC lights will fit. I eventually decided on a 250 MH lamp in a DIY hood, but I feel that much light will be overkill.

2. There's no space behind the tank because it fits in the corner. Unless you pull the tank out from the wall, which defeats the entire purpose of a corner tank, you'll have no space for any hang-on units, which becomes very important because of #3 below.

3. There's no space under the tank. Not even a 10 gallon tank will fit under my 44 pentagon. So you can forget about a wet/dry or sump, meaning you'll have to make due with a canister and LOTS of live rock. I decided to move the tank from the wall so I could fit a 2.4" Prizm hang-on Skimmer.

4. The pentagon makes it difficult to get decent waterflow because of it's strange dimensions.


Everything with this tank has been an issue. There should be a government-required sticker on every corner tank that says "Set this up for SW and you'll regret it".

 

[Clown Monarch]

I've seen those before, but they are for a regular tank, or a hexagonal tank.

A corner tank is basically a square cut in 1/2 from corner to opposite corner. Based on a 3' square tank, thats 201 gallons... By 1/2, appx 100 gallons..

Ok. (this is correct, yes?)

200 gallon corner tank? Wow. I guess you won't have space problems.

 

[Verbalkint]

No.. appx 100 g..

However, now that I have laid that out on the floor with paper, I think that's a bit TOO big...

Maybe 2 feet. x 2 feet on the sides. 3 feet deep (high)

That'd be what? Appx 44, 45 gallons.


Clown, could you not to a 'corner type sump'??

I figure with enough powerheads in the tank itself, and all the filteration taking place under the tank in a sump, you'd not need anything to really 'hang on the back'.

Lighting could be creativly taken care of.

You could have lights along the back part of the hood, near the walls (longest parts), as well as lights with reflectors on the actual SIDES of the top (provided it's high enough.)

Just a thought.

I love the look of a corner tank.

 

[Clown Monarch]

Oh yeah, 100 gallons.

3 feet deep is a pretty deep tank, pretty much dictating MH light. For comparison, my corner is 22" high I think, the same as my 125.

I love the look too. Just make sure you plan everything out carefully before you build.

Mine is a standard corner tank with a basic stand. Since you're building it yourself, you should be alright since you can plan for everything.

There's a door on my stand that's maybe 8 inches wide - trying to fit anything in there is a pain. If you design it with a corner-sump, I think you'll be alright.

 

[BillyZ]

definitely plan plan and plan.

then, when you're ready to build, make it out of cardboard first and put it in place.

Make sure the stand, tank and any hood/lighting is still going to be what you're expecting.


IMO, the best way to do this would be to build in some internal overflows that are plumbed through the bottom of the tank. A couple of 1" PVCs should do you fine. They can be camouflaged in the tank behind LR or a number of things.

 

[BillyZ]

oh... and for finding the volume it's easy. Find the volume of the full cube 24"*24"*36" = 20,736 cubic inches. Then find the volume of the triangle you're removing. if you're going to have 6" "stubs" that come out from the wall, then you're triangle is ((18"*18")*.5)*36" = 5,832 cubic inches. A gallon of water is 231 cubic inches. So, (20736-5832) /231 = 64.52 gallons.

[edit:OOPS! Bad math... fixed bad triangle area formula thingy!]

 

[Verbalkint]

Well.. If my math is right....
The stand would be a bit bigger than the tank dimensions... but small number are simpler..

So, lets say 2 feet for the back sides, 6 inches for the sides that are at a 90 deg angle to the walls.. That leaves a little over 2 feet for the front angle.

Depending on the height of the stand itself, I don't see why you couldn't get quite a bit in there.

A 10 gal is appx 12x12x18 (I think).


What i'd do is build the stand around whats going to go IN it..
If you oversized the stand by as little as 2 inches, you could fit a 10 gal tank (square) in there, with minimal issues.

This would leave you with plenty of room for other 'equipment' under the stand..

I'll draw a few things up this evening in 3ds max, and see what they'd look like.

Just a question here, do you personally thing 3' sides would be too big?

I keep looking it at measured out on the floor, and the more I look, the more i think I could live without that floorspace.

Besides, it'd make my fish happier.

 

[BillyZ]

Just a question here, do you personally thing 3' sides would be too big?

I keep looking it at measured out on the floor, and the more I look, the more i think I could live without that floorspace.

Besides, it'd make my fish happier.

Take my suggestion seriously. Find some cardboard and mock up the tank and set it in the corner. Thats the best way to get a real feel for how it will make the rest of your room feel.

 

[Verbalkint]

Will do. I think i have enough cardboard laying around to even approximate the height of the whole setup. (Refridgerator boxes come in handy i guess, eh)

I'll post later if the wife and I decide that this is a worthwhile endeavour.

 

[Kasakato]

Verbalkint- do you have thoes pictures of the overflow?

 

[Verbalkint]

Oh.. Man.. Glad you mentioned something, cause it goes into the water tonight.


PM me, so that I remember when I get home. or shoot me an email.. (drich at nea-online dot net)


That's usually the 1st thing I do when I walk in the house.

I'll snap a few quickies and post em up on my gallery for ya.

 

[Wizzard~Of~Ozz]

Let's all take a stab at this one shall we?

36 x 6" = 216"^2 (6" side one)
30 x 6" = 180"^2 (6" side two, less 6" already calculated)
30 x 30 = 900 / 2 = 450"^2 (Triangle considered Square, then cut in half)
--------------------------------
846 Sq. In..

* 36" High = 30456 Cubic Inches

or

30,456 * 0.0043 Gallons per Cubic Inch = 131Gallons.

As for the back, I would use 3/4" Plywood and put 1/8" plexi or acrylic on the surface, use silicone to seal it, that way you can paint the plywood black, use a clear silicone to seal the plexi/acrylic to the plywood (apply a lot, spread it evenly, then you can put Plywood (masonite might be better for a smooth surface),acrylic/plexi, then silicone coated plywood on that, then park your car on it to evenly spread the silicone thinly

it's guarenteed leakproof, looks nice and also has a very smooth glass like finish. The bottom I wouldn't worry about too much, but if you do it the same the seals will be nice and tight when siliconed. I know it increases the cost by about 40$ in plexi (it doesn't have to be a very high grade/clarity of plexi), but last thing you want is 130 Gal of water on your floor.

I don't know enough about acrylic to say what would be strong enough, but I know 1/2 and possibly 3/8" should be good enough provided the top is secured to stop it from caving in (nice steel angle iron on the top to make the frame should do wonders, perhaps on the bottom aswell.) if you can get someone to weld it for you.

 

[Verbalkint]

Bingo.. Thank you sir.

Talked with the wife about it.. She's ready to go.. Suggested we 'prefab' it with cardboard, per your suggestion Clown.

She agreed that would be prudent.


Just a quickie, cause this is most likely the most expensive single portion of the whole thing, and thereby determine the overall size of the whole project, how thick would acrylic need to be to support 131 g of water, with a size of appx 33" high x 42" wide?

 

[Wizzard~Of~Ozz]

Edited post above to include some thoughts

looking at a chart, 3/4" is recommended, I though acrylic was stronger then glass, might be worth your while to find out how much a 5/8 3' by length (42.4") of tempered glass would cost, might have to be special ordered tho

 

[austinsdad]

You guys are good....!

 

[BillyZ]

oh you were goin back to a 3' tank? sorry... all my calculations were assuming a 2 foot tank. :?

 

[Verbalkint]

I thought acrylic and silicone were a no-no??

Anyway.. you're saying 3/4 plywood, with 1/8 acrylic on top?

Doing that, it'd prolly be better to build the tank proper out of acrylic, then lay a plywood 'frame' around the 4 sides (2 back, 2 6" sides), Which would defeat the whole purpose of using plywood (cost reduction)


Right now, 3/4 BIRCH 7 PLY is appx $43.00 at my local Lowes. I'd need at least 2 sheets, so lets call that 90$'s.

Acrylic Sheet 48" x 48" 3/8" Thick can be had for about $130.00.
(with a 2' sides and height, Acrylic Sheet 24" x 24" 1/4" Thick for $18.00)

Doing just the 'window' of the tank would require less than this, tho I am having trouble finding custom cut places around me.

Then, with Other materials (epoxy for the wood, paint, etc etc), I'd be looking at around $300 finished.

If i go acrylic on the whole thing, that will more than double the finished cost. ;-/