Advise on drilling 75 gallon Oceanic Aquarium

[austinaquaman]

I got this aquarium a couple of weeks ago and have been putting off drilling it. I am a little nervous about getting it right and would like some input. Also, I would like to keep this reasonably budgeted.

What I want: I want to use it as a wall divider coming out from the wall.

What my girlfriend wants: something that looks clean, preferably with as little equipment showing as possible. Preferably as little noise as well (I know no noise is impossible).

What I know: The bottom is tempered so I cannot drill there.

My current thinking: I am thinking about drilling the side (18" wide x 21" tall) that will be against the wall and then camouflaging the pipes or building something (a box) to conceal them. If anyone has any advice here please feel free.

I am also curious about where I should drill the holes. Further down the tank might make it easier to conceal them.

Another concern is the size of holes to drill for a 75 gallon. What size holes and pipes and how many should I have for the drain to my sump and the return to the tank. I'm not sure how this affects the gallons per hour. I do not have a return pump yet so I am open to ideas there as well.

Thanks,
John

[marshall.read]

if you drill at the bottom of the side, then you'll need an overflow box that extends down to the bottom of the tank. This will conceal the plumbing inside the tank, keep the surface of the water clean, and keep livestock out of the drain. to help quiet it down you'll want a durso standpipe in the box. without knowing what your pump will be its hard to say what size/how many drains you will need. One large drain ( say 2" ) will handle a lot of flow but will make bulky plumbing. smaller drains will have smaller plumbing but you will need multiple drains and you don't have a lot of room on the narrow side of the tank for drains. if you want to maximize flow and minimize noise, then you'll want a siphon system. to do this safely you'll need 3 drains. i used this method when setting up my 135 and it works extremely well.
http://reefcentral.com/forums/showthread.php?s=&threadid=1310585&perpage=25&pagenumber=1

[austinaquaman]

Marshal, thanks for the information on the drains. I am leaning towards the 3 ~1 inch drains the link you provided talks about. It makes a lot of sense.

Does anyone have any thoughts on the return to the main tank? Could it be on the same side of the tank as the drain? Advantages/disadvantages and recommendations are welcome.

[marshall.read]

it would improve circulation if it was on the opposite side, but since the tank is a room divider and you don't want to see any plumbing i understand your reasoning. were you planning on drilling the tank for the return or going over the top of the tank? if your plan was to drill the return then you need to put it on the other side of the tank. you're already talking about 3 2inch holes (more or less depending on the size of your bulkhead) on the narrow side of the tank. you need to leave a few inches between each hole in order to maintain the structural integrity of the tank. as it is with three 2" holes you would have about 3" in between holes. I would consider this a bare minimum. before you proceed to drill i would get some additional opinions about whether or not this is advisable. if the return is going to be on the same side you will need to run it over the top of the tank and you will need a koralia or something on the other side of the tank to generate some movement.

[ErikH]

I would use either 1 or 2, 2" drains with a calfo style overflow. If you build a stand to contain the sump, the falling water will be less noticible. I say use 2" just in case a turbo snail decides to take a trip down, it won't stop the flow of water. Use duro styled pipes (basically a T fitting coming off your bulkhead) and put a cap on the top with a hole drilled into it to allow air in the tube which will stop the gurgling. I figure if you slanted the over flow it would be more quiet. By slanting, I mean taking the overflow box, and the main piece, should stick out further at the surface then it does at it's base. That way water does not spill over into the overflow box, it would gently glide over the edge and into the box. Also, a small return pump like a mag7 should help keep it quiet and provide enough turnover for your application. If you don't want powerheads, you could add a SWCD. If you do add a SWCD, you may want to notch up to a mag9 or 12 to provide enough flow without powerheads. The new style SWCDs are much more reliable and do not have the tendency to stick as much anymore. Otherwise, you may need to craft a return system with some PVC and drill holes.

[brewercm]

You could also build a return manifold that wraps around the top of the tank and put as many returns from it as you want. That way you can get flow from the other side of the tank from the overflow.