Need help designing my 37G tank

[hartman]

Hello All,

I am building my new display tank off my old 20G. The 20G was a long 30x12x12 on an All-Glass stand. I plan on reusing the stand but putting the 20G as the sump and the 37G 30x12x22 as the main tank.

I will be buying the following stuff:
<b>New Lights</b> = IceCap 660 with (2)75W days and (2)75W 03 bulbs
<b>Pump</b> Not sure I have a spare Mag7 But I think I will need 2, one for the sump return and the other for the closed loop.

Things I would like to do.
1) Have no power heads in the main tank.
2) Get an 8-inch SB in the 37G.
3) Use my old PC 2x55 lights on the sump.
4) Drill the tank along the back for the closed loop and the overflows

I want to make the overflows as small as possible; do they need to be the full height of the tank? I would like to make them smaller since they are exiting out the back over the bottom? Should the holes be at the bottom of the well to make them quiet?

Also if I have (2) 3/4 outflows, do I take the total diameter of the out and match it to the return? I.e. (3) 1/2" returns?

I will make a diagram and post it later.

Thanks
Hartman

[hartman]

here is a pic of the overflow

http://www.longfleet.com/reef/overflow.bmp

Thanks
Hartman

[David Grigor]

Hartman,

Food for thought.

I have a 37g Oceanic ( 24X20X18). I put in a corner overflow ( without sump ). I have powerheads located in the corner overflow ( to hide them ). It houses the heater the skimmer input and water topoff. No sump but has all the advantages of the sump ( except for the additional water volume ).......The MJ serve as returns from the overflow so no returns pumps needed. MJs in the corner overflow IMO provide plenty of flow in that small of tank.

I wouldn't change a thing........

[stavman]

Hartman,

Good luck on drilling a 37 gal. tank. Most of them are tempered. You can check it out at the all-glass.com website to see if your specific tank is.

Very nice diagram by the way!


David,

What did you use to attach the corner overflow, assuming it is acrylic or some plastic, to the glass of the tank?

I have a similar plan for an Oceanic 37 where instead of a corner overflow, I plan to put a piece of black acrylic across the entire width and height of the tank 4 inches or from the back to make an internal sump/refugium.

thanks,
Joe

[David Grigor]

I just used black silicone. Since it was a corner overflow, I didn't have to worry about it much because the pressure of the water is working in my favor to help keep it in place.

I do however have a 25g breeder that I did what your saying and put a overflow type partition across the whole back. As long you keep the water level in the overflow portion close to the same height as the main tank there shouldn't be too much pressure on it. On the inside just extra goop it and should be fine..... To be safest I would add a brace or two of acrylic ( on the inside of the sump area ) perpendicular that attaches to the back glass to help reinforce so that any water pressure from the main tank would be supported by more then the silicone on the sides of the glass.

I thought about doing what your debating with my 37g. But I really wanted to keep as much front to back room for aquascaping so went with a corner one. It is big enough for everything I needed to put in it ( Allbeit not much room ).

I do not know of a fool proof method of attaching acrylic to glass.....

[Pyrojon]

Hartman,

I don't understand, if your tank is drilled (or will be) why use the inside box? Why not turn your output tube upside down. (So it looks more like an S on it's side, then an upside down U) and put a screen on the end. (does that make sense? I whipped up a quick pic. Find it below.) I see many LFSs using this exact system. The part on the outside (top of the T) is designed to quiet the overflow, just make sure that it terminates higher then the water level.

This way you can adjust the height of the water by rotating the output tube inside the tank. Then you don't lose the space that the overflow box takes inside the tank, and it doesn't look as bad as a plastic box in the tank either.


good luck
Jon

[hartman]

stavman,

According to All-glass site it is not tempered. I might have it custom drill from them. If I do it myself I will put pieces of wood on either side and hold them on with easy-grip claps. This will support the glass around the hole during drilling. I will also grease it up to help with friction.

For the overflows I will cut acrylic and use just aquarium silicon.

The reason I want small over-flows is I don't like the full height look

Hartman

[Pyrojon]

The pic

The part on the right should be able to rotate, so that you can adjust your water level. The part on the left is a T, the top is open to the air and should terminate above the water line, this is designed to silence the water flow.

[David Grigor]

Since all-glass 37g is so skinny and would loose valuable front to back space with any overflow. Perhaps putting a full partition/overflow on the side. Here is a pic of a 14g Nano my wife has in her office...... It is up against the wall now but the tank was designed to be seen from 3 sides......

[David Grigor]

Side View:

[hartman]

Pyrojon,


Thanks I was hoping to find a way to elimanate the overflow box. Beyond flow amount does it pay to have bigger overflow pipes to make the system quiet? I was thinking of maybe 2 - 1" downs and a bunch of 1/2 up for the return and a 2 - 1" out for the closed loop and a 4 1/2 returns.

I will draw a diagram of the holes along the back of the tank.

David Grigor,

I like that but my stand is a open on the back, but maybe if the bottom of the tank is not temperd them I can do that. I wil just need to fill in the back.

Thanks again guys

Hartman

[David Grigor]

This is just thinking out loud -

If the overflow was the entire length of the side you still could have the bulkhead to the (optional ) sump on the back. you could put the closed loop phs or pump in the over flow and drill a hole in the side acrylic overflow for the closed loop output or go over the top. Would be one less hole drilled in the tank and less plumbing outside the tank. There would be no boxes in the show part of the tank. The overflow being across the whole 13" ( or however wide ) would be plenty of surface area for both return and closed loop flow.

[hartman]

David Grigor,

Sounds good but what about water movement at the far end? Would I run the returns in the hood and then down at the other end?

The tank bottom is tempared so that is out.

Hartman

[stavman]

Hartman,

I just checked the All-Glass site again in the Technical Info section under Services: http://www.all-glass.com/services/index.asp and it says the following:

Tank size: 37 Gallon
Dimensions: 30 1/4 x 12 1/2 x 22 3/4
Weight empty: 45
Weight full: 415
*** Tempered bottom: yes ***


You should double check for yourself at a LFS by looking at the bottom of the tank and see if there is, if I can remember right, a yellow or orange sticker that says "Do Not Drill - Tempered Glass."

[stavman]

Hartman,

Nevermind. You figured out that it's tempered already.

[Agu]

Hartman,

I have a 40 breeder drilled in the back and plumbed as Pyrojon had illustrated. If you had two of those drains at 3/4" draining a mag 7 that would be just about right. And do the T with the vent or those things will gurgle like crazy. I wonder about drilling all those additional holes in the back of a tank though. I don't think the glass is thick enough to handle all the holes and attached plumbing, but that's jmo.

Lighting is an icecap 660. Two uri aquasuns and two actinics was way too blue for me, I just put in a third aquasun and it's just right. Again, jmo,

Agu

[hartman]

Agu,

Not a big deal I could add some acrylic on both sides of the glass to give it strength.

Sill working on the drawings

Hartman

[hartman]

Ok here is a pic of my 3 side view idea.

http://www.longfleet.com/reef/37G_tank.jpg

What you think?

Hartman

[hartman]

Anyone :)

Also I was thinking of running the closed loop on a 30 min timer to make wave motion. So sump return will go across the top at the surface.

Hartman

[hartman]

Here is an updated design.

http://www.longfleet.com/reef/37G_tank2.jpg

Thanks
Hartman

[Agu]

I would say, "I don't think the glass is thick enough to handle all the holes..........", but I already said that.

A single return, possibly with a spraybar should be able to handle the overflows. If you make the return a hob you can eliminate two holes. The holes for the overflow don't need to be that low, mine are only about 2.5 inches down. Build the overflows, figure the water will be above the drain about 3/8", and then determine where to drill.

Like the "low" drain for the closed loop, but you better hope the bulkhead never leaks.

The half hour on/off sounds good on paper, but from what I've heard and read you'll burn out a mag 7 pretty quickly doing that.

jmo, ime,

Agu

[David Grigor]

If I understand the drawing correctly......

With a side overflow like that water would enter from the overflow teeth at the top so the purple intakes are not necessary.

If the whole width of the tank was the overflow and had teeth all the way across it should handle all the flow without the purple intakes. My corner overflow has teeth on two sides which are 9+6"=15" total and I push more about 2000gph through it so 12.5" of teeth would probably handle both return & closed loop.

[David Grigor]

You could also make simplier having the return from sump come back on the opposite side and have the closed loop just come in on the same side as the overflow.......

[Pyrojon]

Regarding your revised idea with the tube underneath the sand bed.
I tried this and it lead to many problems.

My current reef is a 90g, setup similar to your plan, viewable on 3 sides. I realized that I would have very little current flow on the far side so I thought I would bury a length of pvc in the sand to move water from one end to the other. It didn't work well. It got clogged and water sat in the tube stagnant for a while, then when it was unclogged the stagnant water was a mess.

I ended up with 4 hefty powerheads on the equipment end pushing current to the far end. I dont get a whole lot of current at the far end, but that only gives me an area when low current corals can thrive.

I'm somehow not femiliar with the term "closed loop" (I havn't been keeping up with the reef community lately) but what I gather is that it's a way to create circulation and do away with the ugly power heads in the tank?


Also, you don't want to have your outputs low in the water at all. Imagine if your power goes out AND one of your check valves jams open. 37 Gallons is ALOT of water on the floor.


Good luck
Jon

[David Grigor]

If all the outputs that are under water are part of the closed loop ( not going to/from sump; it's own entity ) then then the only risk is any plumbing for the closed loop where to fail. If the closed loop is all internal to the tank then it would be impossible.

[hartman]

Thanks guys I will make the changes. I see the problem with the sump returns and if power goes they will drain the tank. I will fix that by putting them above the water level.

As for the under the sand bed I plan on making so I can clean it. At the end outside the tank I will put a "T" where the down is to the pump and left is a screw cap than I can pull and send a pipe cleaner in. They way it works I put a cap on the end in the tank and open the other. Maybe this a still a bad idea.

Hartman

[David Grigor]

No harm it you can plug it up if necessary. Personally, I would prefer all water to go through the top overflow teeth to get the max. gas exchange rather than from the middle of the water column plus no chance of sucking things up.....

[hartman]

David Grigor,

I will design it with the overflow box like you say, give me a few hours.

Hartman

[hartman]

Here we go.

http://www.longfleet.com/reef/37G_tank3.jpg


Ok if Mag7 does not like on/off then I could use it as the return and get and Isaki as the closed loop.

Thanks
Hartman

[David Grigor]

Actually, The only way that would work is if the closed loop hole is lower than the sump hole and the sump hole incorporates a durso type mod where the water level in the overflow stays high. If the holes are the same height then the water in the overflow will totally drain and cause air in the close loop.

Hard to explain without paper and pen. Hopefully you can invision.


With the durso type mod on the sump hole you want to keep the water level in the overflow high enough so that the closed loop would always be under water.

[hartman]

Got it, making a new drawing now. Question, what size PVC should I use? 3/4 for the overflow and closed loop out and 1/2 back to the tank?

Maybe on the far end I will need a Sea swirl.

Hartman

[David Grigor]

I would go with the standard 1" bulkheads. You can always reduce but harder to go bigger plus if you drill yourself the 1.75" bit is a more usable in the future......

[hartman]

David Grigor,

Thanks, where can I get the bit, Sears and HD have nothing bigger than 1/2 inch.

Here is version 4
http://www.longfleet.com/reef/37G_tank4.jpg

Hartman

[David Grigor]

Got it backwards. The purple one should be the sump hole. The water level in the overflow will settle at the top of the fitting. The closed loop hole should be as close to the bottom as possible with no elbow. You want it to stay fully submerged.

I can tell you that 1/2" is WAY undersized. I had a 33g tank with mini-sump. I was using to two 1/2" bulkheads and it could barely keep up with 175gph.


http://www.shopsmartxpress.com/AmeriGls/W9.htm is where I got mine. So far I have cut 10 holes in 20g high tanks with it. I figure it is good for another 10.

[hartman]

Thanks

OUCH = TL-481 1-3/4" Diamond Core Drill Bit 41.95

Look again the left outflow is high (sump) and the rigth is the closed loop. So you think the elbo on the closed is worse than and open lower hole?

1" out and 3/4 back?

Hartman

[David Grigor]

Looking at the diagram the hole on the right that has an elbow pointing downward is the one that should be to the sump ( like original overflow pic on the 1 page ). The other one just open hole with maybe a bulkhead screen. This hole needs to be positioned as low as possible.

If you left the red the sump hole it's going to gurgle and make all kinds of noise.

$41 - Around here at best the going rate per hole is $25. Two holes and you have broke even on the investment. Nice to have the bit handy now your not limited with sump configurations etc. with a glass tank that most people fight. Also, the bit has plenty of life left and you can lend it to other reefers in the area for a fee. For me it was a no brainer because I did 10 holes.....

[hartman]

Thanks All,

I am going to test the plumbing this weekend and I will keep you updated.

Thanks
Hartman