Note: Please keep in mind that there are a couple of ways to set up a sump. The way I'm going to describe below uses a durso standpipe on the outside of the tank with a wedge shaped weir. I personally think this will be the best way because it means the least amount of space taken up in the display tank. It unfortunately is not very easy to explain in writing and I have probably made it sound a lot more difficult than it really is.
Note2: Any images are not mine, they where hastily taken from google images, tried to put sources in where possible).
Overview of a sump taken from www.melevsreef.com
Basically the components of a sump, starting from the top in the tank, are:
Overflow/weir - This is the "overflow" part. Basically a wall that sits just under the water level for the water in the main tank to flow over. Behind the weir will be the internal sections of the durso standpipe (see below) which are attached the bulkheads (which go through the drilled holes) that the water flows out of.
Important note: You need to make sure that the weir is long enough to allow enough water to overflow. More info on calculating flow rates, etc lower down.
Bulkheads - These fit inside the holes that are drilled in to the side of the tank. On the outside (of the tank) the bulkheads attach to the durso standpipe (see below) which drain the water down to the sump tank.
Important note: You need to ensure that the bulkhead size is big enough to allow enough water flow. Also I would always recommend having two bulkheads so that if one ever blocks you wont get the display tank flooding.
Durso Standpipe
One of the disadvantages of a sump tank is that the overflow can get fairly loud with the sound of running water (especially with an open topped tank). However there are ways to make it a LOT more quite. One of the main ways of plumbing in the drain pipes is using something called a durso standpipe. I wont go into massive detail on them here as there are lots of sites out there that explain them (will try and put some links in at the end). For a rough idea though they look like this:
The bit in the tank is a 45degree bend so that the end of it is under the water that is behind the weir.
This goes out the bulkhead to the back where it goes into a T piece. The top of the T piece goes up into an end cap which has a small hole drilled into it. The hole is very important as this allows some air into the pip and prevents a syphon from forming. The size of the hole also effects how loud or quite the system is and can take some playing with to get just right (normally you don't need it too big).
The bottom of the T piece goes down to the sump.
Links:
http
/www.dursostandpipes.com/
http/www.wetwebmedia.com/diy_durso_pipes_jg.html
Plumbing down to the sump
I would recommending not having the pipe dropping straight down into the sump. Personally I would put a couple of small bends into the plumbing to help slow the water down and reduce noise. There are disadvantages to this (such as reduced flow and increased chance of blocking) but if you have 2 bulkheads anyway this isnt much of an issue.
The sump
The sump can be any water tight, fish safe (ie I wouldnt use anything made out of copper if you have shrimp/snails), container large enough to fit the filter media you require. Typically most people will use a cheap glass or plastic fish tank.
The basic sump is normally divided into 3 sections. The first section is where the water from the display tank drains into. You can also put your heaters and stuff in here. You then normally have a baffle which stops all the bubbles where the water goes into the next section.
The second section is normally where you have your filter media. This can be divided into smaller sections for pre-filter (mechanical filtration), bio filtration (bio-balls, etc) and then a section at the end for chemical filtration (such as activated carbon). You then have a baffle to stop any bubbles or filter media going to the next section.
The last section is the return chamber. This is where the return pump sits which pushes the water back to the main display tank.
In regards to sump size you want the biggest you can fit in really. Bigger sump=more water volume and more filter media.
Important note: When filling the sump tank you dont need to fill it right to the top. You need to leave enough space in it so if the power to the pump ever fails there is enough room for the water that will be syphoned through the return pipe (more info below).
Link:
http/www.cichlidmania.net/index.php?pid=16
Return Pump
Ideally you want the water volume of the display tank to be turned over through the filter at least 5-7 times per hour (can someone please confirm this as im not sure im remembering the ideal flow rates for filtration correctly). You also have to take into consideration the "head loss" (how much flow the pump loses when pumping water straight up).
So you need to look for a pump rated over 500-700GPH. Pumps should have a graph on them which tell you the flow rates at different head heights. For example if you the top of your tank is around 5ft tall you need a return pump that will have an output of 500-700gph at a head height of 5ft. You will probably need around a 1000gph pump but it depends a lot on what pump it is (some are better than others).
If you get one that is too powerful you can also put a T piece on the return pipe work with a valve on one bit with pipe coming back to the sump. this will allow you to adjust the amount of water going to the display tank.
Return pipework
This goes from the return pump back to the display tank. You can have the tank drilled to have the return pipe attached and it would be neater but you could also just have the pipe going over the edge of the tank into the display.
important note: On the return pipe make sure that is is well secured in the display tank (last thing you want is for it to fall out and spray ever thing with all the water in the sump). Also just below the water surface on the pipe make a small hole. The reason for this is that if the pump stops working the return pipework will turn into a syphon pulling the water from the display back into the sump tank. If you put a small hole in the return pip just below the water it will back syphon until it hits the hole and then it will suck in air which breaks the syphon (so only a small amount of water will syphon back into the sump tank).
Some maths
I cant put the link on to the calculator I used as its on another forum (pm me if you want it). However assuming we want 7 times turnover through the filter (700gph flow rate) we need:
Recommended minimum drain pipe diameter = 1.09 inches (I would put in two 1.5" drains)
Recommended minimum linear overflow size = 11 inches (I would make it at least 12 inchs)
I think I have covered all the main points. If you speak to the people making your tank they should easily be able to drill the correct size holes and put in a weir (they can probably provide the plumbing for it too).
Some extra links:
http/www.melevsreef.com/allmysumps.html (great site)
http/saltaquarium.about.com/cs/bcorsetti...020298sumps.htm
