Drop off reef design - Starphire

[karimwassef]

Considering a new tank and this idea is intriguing. The main tank is 24" deep, but the drop-off section is 48" deep but only 30" long.

It's a wide tank design too, 72" is most likely. The length is likely 112" overall.

Given that the majority of the tank is 24" deep, and the deep section is relatively small (only 30" long), would a 0.5" glass pane work?

<a href="http://s1062.photobucket.com/user/karimwassef/media/dropoff_zpsvyt0cts5.png.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/dropoff_zpsvyt0cts5.png" border="0" alt=" photo dropoff_zpsvyt0cts5.png"/></a>

How would the L shaped glass be cut? My first thoughts are to make it as two tanks at two different thicknesses. The shallow section at 0.5" and the deep section at 0.75" or 1"

Looking to learn here -

 

[karimwassef]

alternatively, the shallow tank can extend to the full length and only the deep section at 1" thick?

I changed the color of the thicker glass for clarity

<a href="http://s1062.photobucket.com/user/karimwassef/media/1_zpswcma6hkz.png.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/1_zpswcma6hkz.png" border="0" alt=" photo 1_zpswcma6hkz.png"/></a>

 

[karimwassef]

Of course, the ideal is to go seamless with a 0.5" L plate on either side.

<a href="http://s1062.photobucket.com/user/karimwassef/media/2_zpskrrztimg.png.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/2_zpskrrztimg.png" border="0" alt=" photo 2_zpskrrztimg.png"/></a>

It's a peninsula tank, by the way. So the L plates on either side are self supporting.

 

[Achilles Torben]

http://www.reefcentral.com/forums/showthread.php?t=2511159

 

[karimwassef]

Here's the surroundings. No additional support.

<a href="http://s1062.photobucket.com/user/karimwassef/media/3_zpssichjr34.png.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/3_zpssichjr34.png" border="0" alt=" photo 3_zpssichjr34.png"/></a>

 

[karimwassef]

http://www.reefcentral.com/forums/showthread.php?t=2511159

thanks! Looks very similar, but I'm looking at being a lot longer and wider. I know it can be done, but can it be done with 0.5" thick glass and a seamless L shape at 112" x 48" with a 24" x 30" deep section.

It's 1065gal in the DT.

 

[scuzy]

At that size why not acrylic?

 

[karimwassef]

Several reasons. First, scratches. I have sand and every acrylic tank I've had is worthless after a couple of years. Starphire is soft too, but more resistant to scratches.

I also don't like the way acrylic bows out at >8ft.

I also want as little top support as possible.

 

[dave.m]

I would suggest 0.75" glass if you are going low-iron (e.g. Starphire). I would also strongly recommend euro-bracing, both top and bottom.

Dave.M

 

[FloformAustria]

what you have planned there is really nice!
next tank i will also wider!! 70cm isn´t enough, thinking 130cm to realize a nice drop-off and i also would make the deep part longer. mine is 55cm, next one will be around 70cm.


the glass is not the problem, but you have to look out how they cut it. my builder made a round inner edge where the drop is. otherwise there would be too much tension in that area

Cheers

 

[karimwassef]

I would suggest 0.75" glass if you are going low-iron (e.g. Starphire). I would also strongly recommend euro-bracing, both top and bottom.

Dave.M

That would be the safest, but I'm looking for what's safe enough.

I'm ok with bracing on the bottom and maybe a thin lip on the top. I'm ok with 0.75" on the deep bottom and vertical planes. The big question is if 0.5" will work for the L sides.

I limited the majority of the tank to 24" to be able to use 0.5" glass to control the cost on this massive build.

 

[karimwassef]

what you have planned there is really nice!
next tank i will also wider!! 70cm isn´t enough, thinking 130cm to realize a nice drop-off and i also would make the deep part longer. mine is 55cm, next one will be around 70cm.


the glass is not the problem, but you have to look out how they cut it. my builder made a round inner edge where the drop is. otherwise there would be too much tension in that area

Cheers

Thanks. Great tank, by the way, and great thread.

I was thinking that it would need a large enough radius to reduce stress. It's a long plane too. I went shallow based on the depth but with a linear run of 70" before the drop and another 30" after, I was concerned about the non-water weight.

For example: my own weight as I reach over the lip to place rocks or the weight of a rock balanced for a few seconds on the edge. Not that I plan to be rough, but those things happen. When it was 24" deep all the way, I think the 100" total run wouldn't be so risky. But the addition of the deeper section made me think again.

I discovered drop-off tanks this summer while researching designs. I prefer shallow tanks because I grow SPS and high light coral. I also find that a wide tank has very limited access so being shallow is key to access.

I have a 27" deep x 32" wide now in an in-wall build and have lost frags because I couldn't get to them without wrecking the rest of the tank. In-walls have the worst access. They feel like 2x the width on a peninsula so like a 27" deep x 64" wide. I even have 3" of sand and the bottom 2" is just unreachable. It was ok when I just had rock but the coral grew and the branches create a mesh that restricts my reach. Didn't plan on that...

However, there are some coral that like it deeper and 48" introduces new ways to create flow patterns and thermal zones. It also creates a more dynamic fish environment. But it had to be where I had full access almost (3 side) and only 30" away from the edge. There's still that area in the middle (30"-36" for any edge and 48" deep) that worries me. No branching coral over that window!

 

[karimwassef]

You know, sometime talking (or typing) out loud helps crystallize things. Even with 3" of sand, the innermost section in the bottom of the 48" L would be a 54" reach (30" from the edge x 45" down with 3" sand). Anything that ends up there and needing help would be like performing surgery with very long instruments...

I think I'll look at a 36" drop off? That would shave 9" off the worst reach section on a diagonal (down to a 45" reach at 30" from the edge x 33" down). Maybe the 30" run can come down to 26" too.

That would lose some of the vertical deep wall effect I wanted, but I'd lose less coral to the abyss.

 

[FloformAustria]

The funny thing is I have convert all the " into cm to get any feeling for the dimensions xD
But if it is too deep for any proper handling you should really consider a change

I'm 192cm tall and to get something out of the deep areas of the drop I have to get into the tank close to my shoulders...

 

[karimwassef]

I use sketchup, so I can just change units and repost

Now you know how we Americans feel seeing cm and mm. Outside of engineers and scientists, all vendors operate in inches.

 

[karimwassef]

Just for our cm brothers and sisters...

<a href="http://s1062.photobucket.com/user/karimwassef/media/0_zpsbf6lgk1j.png.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/0_zpsbf6lgk1j.png" border="0" alt=" photo 0_zpsbf6lgk1j.png"/></a>

 

[d-man]

Can't wait to see this one.

 

[FloformAustria]

Thanks! That is going to be a big *** tank!!

Looks way better in cm

 

[karimwassef]

well.. this is a long term design, and a lot of things have to come together. I'm just now starting the design.

So. I took your feedback and my own fears (send some questions to my tank builder), and decided to scale back and shift things a bit.

12" of the tank will be made into a directional flow machine against the far end. That's why there are separators there. The overflow is a weir-like section in the middle.

<a href="http://s1062.photobucket.com/user/karimwassef/media/0_zps7mhsjopg.png.html" target="_blank"><img src="http://i1062.photobucket.com/albums/t496/karimwassef/0_zps7mhsjopg.png" border="0" alt=" photo 0_zps7mhsjopg.png"/></a>

So, the deep section is 42" (which I think is still pretty deep) or 18" deeper than the shallow section x 24". I extended the shallow section instead of making the whole tank shorter.

I also added a double stack of 0.5" rim support at the bottoms. The first is a 3" rim, overlayed by a 2" rim.

At the top, I went with a double stack of 0.5" x 1" rim - just for the little bit of confidence I think it would give me.

The L sides are 0.5" starphire. The deep face is 0.75" starphire.

The shallow bottom and far side are 0.5" regular. The deep bottom and hidden side are 0.75" regular.

 

[karimwassef]

It feels more balanced now.

Flo - anything you wish you had thought of before your build that I should give some consideration to?