New Tank, Build 90gal - Bean Overflow

[rrmoore]

Hello,

I'm jumping back into the reef addiction after more than a decade's absence. (I'm off the wagon).

This time I thought I would go with the biggest tank that the space would allow, without being prohibitively expensive, 48"x24"x18", about 90 gal. (I may go up to a maximum height of 24", 105 gal, but I have a feeling that size may stretch the wallet too thin). Both sizes meet the guideline for promoting good gas exchange, that being width >= depth, per some other thread that I read.

Because the LFS don't have what I want, rimless, three-sided low-iron glass and drilled for a Bean overflow tank, I thought I could buy the tank and then do the Bean installation my self. I chose the Bean overflow for its noiseless operation, redundancy, self-starting, adaptability and scalabilty characteristics. So after countless thread-reading hours I thought I would ask the group if the following measurments for the hole locations and dimensions would be correct.

All holes are being drilled in the back. Also, they should meet the requirements for the actual plumbing as documented in the Bean webite. The three holes will each be 1 3/4" in diameter.

All measurements are from the top of the glass, and with the prespecitive from behind the tank.
1) 1" from the top of the glass will be the top of the weir.
2) 1 3/4" will be the top of the hole. Would 2" provide "so much more" structural integrity, that I would want to make that adjustment?
3) 2.625"/2.75" (rounding) will be the center of the hole. Since my tank won't have trim, I can get away with 2 3/4".
4) The three holes will be started 2" from the left side measured from the exterior left side panel. Instead, should the 2" be measured from the interior of the left side panel?
5) Each will be drilled 2" from each other. measured edge to edge. I chose 2" just because it's a nice round number, and meets the requirement that the holes be located at least the hole's diameter apart. (The accumulated extra 3/4", to the right edge of the third whole won't be noticeable.)
6) One return hole whose center will be 3" from the right side for a 3/4" return. This hole's top edge will be 1 3/4" from the top of the glass, unless the hole size requires a lower top edge. (I don't know the size of this hole. Anyone know?) The horizontal measurement will place the hole dead center between the right side of the tank and the beginning of the weir. The vertical distance was chosen so that the return would be below water level, and when power is lost only about 15 gals of water will flow into my 40B sump. I plan on installing a check value on this return.

I'm also planning for a coast to coast 1/4" clear acrylic 42" weir, originating on the right side.
7) The weir's dimensions will be 42"x3"x(1 3/4"+ 3/4"+distance from siphon's elbow's center to its downturned opening). Again another calculation found in an earlier thread.

Aesthetically, these locations and sizes should meet my other requirement, ie eliminate visual clutter; over the rim returns, colored weirs etc. I'm not painting the back of the tank, because I want the tank to look like a block of water resting on a stand rather than a window into a coral reef.

The above calculations were obtained in the Bean thread, entries #6224 and #6228, and the Bean webite. They should also provide me with my planned 5x DTS turnaround, and the ability to go higher. (I want to save the sump and flow discusstions for a later time).

So, what do you think of these measurements? Although I feel confident with these measurements, I'd feel much less stressed with a second opinion. Feel free to offer comments about hole locations based on aesthetics but meeting the requirements of their intended function.

Thanks to all in advance for taking the time to read this and respond.

[Fish'InMN]

All of your dimensions sound fine except the return hole diameter/bulkhead - just use the same size as your drains. Keep it simple with all plumbing the same size, get the benefit of less restriction on your return pump (which probably should have 1.5" plumbing anyways).

You could extend the weir across the entire length of the tank and have the return plumbing go through or over it. 'Through' the weir with a uniseal or another bulkhead, 'over' the weir with a few 45's, etc. This looks a bit better in my mind than a weir that abruptly ends just inches short of the other side but to each his/her own!

[rrmoore]

Thank you for taking the time and effort to look over my ideas.

The idea about going through the weir for the return is a great idea. I had originally thought of continuing the weir across the entire 48", but my retun was placed underneath the weir. I felt like that placement was just asking for trouble, so I changed it. I like your idea much better.

I'll need to research the plumbing required for the return. I was planning on using a pump that uses a 3/4" hole threaded barb for output. Off hand I don't know the pros and cons of my options by using this new configuration.

Thanks for the diagram of the layout. Is that some freeware that's out on the internet?

[Fish'InMN]

Diagram was done with Trimble SketchUp, previously a Google project.

If you can get the information you will find a large number of pump manufacturers recommend a pipe size larger than the output on the volute. The increased flow (reduced head pressure due to pipe restrictions) will be marginal with most installations but the simplicity of having a box of leftover plumbing parts that are all the same size...

[Jpugh73]

+1 on going all the way to end of tank and bringing return though it