Ok so I have decided on how to drill my tank, just wanted your opinions on my setup and if you forsee any problems.

120 gal low iron/starfire tank, 48"x24"x24", bulit in wall - to be a reeftank, mostly corals/clams with small fish. Will be equipped with sump/refugium haven't decided which size.

I plan to have two external over flows built. Each back corner of the tank will be notched 2 inches down. The over flow box will be attahced to the back of the tank. The over flow box will contain three 1" bulk heads in a line parallel to the back of the tank. The spacing of the bulk heads will be determined by the minimum distance I can place them apart to maintain glass strength. This spacing will determine the length of the overflow box, the bulk head w/flanges will determine the width of the box.

The three bulk heads - first bulkhead to act as the return, the two other to act as overflow's, preferrably the "herbie" method where one bulkhead is attached to a ball valve and the other is the emergency overflow if the ball valve were to become plugged. If the "herbie" method doesn't work, then they can act as single/double durso standpipes.

Each overflow to handle approx 600gph, and a tank turn over of 10x utilizing a pump with reach of 4ft and accounting for headloss to equal 1000 - 1200gph. Additional powerheads to be added to equal 25-30x tank turn over.

Black/other dark colored acrylic to be placed inside tank and cut to accomodate notches as background

Ok so my questions are as follows:

1. Is this low iron/starfire glass the most clear/best glass to use, I realize acrylic can be optically clearer but I want to stick with glass.
2. Should I go with a brace across the middle top of tank, or euro style brace pro's/con's. Do I need a brace at all?
3. What size sump/fuge would be reccomended, I would like to have mandarins eventually.
4. Is the 2" notching sufficient? and how do I calculate the amount of water that can go through the notch ie: 2"x8". maybe I missed one of the calcs at reef central....<shrug>
5. Should the dimensions of the overflow box be the minumum that the bulkheads can be placed in a line to maintain glass strength or are there ideal/better dimensions for legth/width.
6. The height of the external overflow, should I make it the full height of the tank, or only half way down the tank. I was thinking halfway down to allow for easier asccesss/maintanence of installing bulkheads/piping.

I also included a very elementary drawing if my explanation is confusing. I am not an artist, expecially on the computer :)

Would love to hear you thoughts, thanks guys.

To answer your first question, Starfire glass is as optically clear as Acrylic. Second, with glass, I'd go with euro bracing giving you nearly total access to the tank.Third, the bigger the better. I'd say 50 gal min to 80 or 90 gallon. What ever fits under the tank and still allows room for other accessories. #4, this is the big question! Is the tank built, yet? Are you going to knotch it? How are you going to keep critters from going over the overflow? Fifth, the overflow box should be bigger. Otherwise you will be very annoyed with the slurping sound of the drains, IMHO. Sixth, personally, I'd go with internal overflows. Less chance of leaks and less hassle in the long run. You are probably trying to save internal space and present a cleaner look but I would opt for internal.

Hope this helped.

Dick

Amphibious you were mentioning the slurping noises/overflow box size. What would casue this, the height of the overflow box, or the width/length. Whether it is internal/external what size do you think would be ideal. The tank is not yet built, the notch will be done professionally...i hope... :) And screening/egg crate/gutterguard type will be placed in the notch.

tx

Any time you have water draining through a pipe it will suck air with it causing the slurping sound. The Durso style drains eliminate 98% of it. If you go that way, you have to make your O/F box large enough to accomodate the Durso.

i think Amphibious cover the immediate question here..
i just want to re-itterate, that if the tank is not built yet, look at having the internal overflows done, they will be easer in the long run as noted.

and :welcome: to Talkingreef.. :)

that if the tank is not built yet, look at having the internal overflows done, they will be easer in the long run as noted.


ok, so what is it about the internal overflows that will make things that much easier... pro's/con's your experience with either... tx :huh:

first of all, they're not as ugly. we hate having equipment in our tanx, and strive to keep the equipment out of sight as much as possible.

secondly, they are more reiliable as there is no U-tube or CPR-style aqualifter pump to contend with.

thirdly, O/F boxes are more unstable on the back of your tank, and to plumb to.

you could also have the back of the tank slotted and have an external box built onto the back of the tank if you're having a tank built to order.

IMHO, there's no option...you'll like the built-in more.

:up: I totally agree with Saxman.

first of all, they're not as ugly. we hate having equipment in our tanx, and strive to keep the equipment out of sight as much as possible.

secondly, they are more reiliable as there is no U-tube or CPR-style aqualifter pump to contend with.

thirdly, O/F boxes are more unstable on the back of your tank, and to plumb to.

you could also have the back of the tank slotted and have an external box built onto the back of the tank if you're having a tank built to order.


thanks guys, i think there might be a bit of confusion, the overflows that i desired are the ones that are slotted and have the external box. The hang-in-the-back HITB rather than the CPR type hang-on-the-back HOTB. I guess I'm wondering about the extrnal with slots vs. the internal pros'/con's. Anyways, just to clarify, thanks for you thoughts so far though, appreciate 'em.

ah...OK, got it.

since it will be sitting on the back of the tank, the external box built onto the tank will be more prone to leakage/damage than the internal built-in style. then again, the external box doesn't take up any room in the tank...decisions, decisions...