Things You'll Need
- Drawing paper
- Pencil
- Return pump
- Sump container(s)
- PVC pipes and parts
- PVC primer
- PVC glue
- Live rock
- Sand
- Macro algae
Instructions
Planning
Draw a scale replica of the aquarium and all parts (such as the stand). You can do this on a computer or on paper. Sketch some ideas on the paper for how the sump will look. Identify empty areas of the set up where you can add additional containers for the water, such as extra aquariums, buckets, tubs, or hang-on filters. Make sure everything is drawn to scale.
Sketch the plumbing on the scale drawing. The amount of plumbing you will need depends on how you will set up the sump. If you are setting it up underneath the main display aquarium, you will need plumbing coming down to the sump, and up from the sump back into the aquarium. PVC is a common choice for plumbing since it is cheap and seals watertight although flexible tubing will also work.
Review your drawing and plan. It is a good idea to take your drawing to a local fish store that specializes in saltwater fish and have them review your set up. They may be able to identify potential hazards or incompatibilities you did not foresee. Additionally, they can recommend the hardware you will need for the set up such as a protein skimmer and a return pump.
Building the Sump
Purchase the items you will require to build the sump except for anything living (such as live rock). Having everything you need will speed up the construction process. If you are using PVC, you will need the pipes, bends, bulkheads, unions, a saw, purple primer, and glue. You will also need the containers you will be using to hold the water and form the sump. You will also need the return pump and any filtration devices you will use. If you purchase living things now (fish, live rock, live sand, etc.) they will likely die before you are finished. Wait to purchase these until the sump is complete.
Dry-fit all of the parts together without adhesives to make sure everything fits. You will need to cut the pipes to the proper lengths and fit the bends. Make sure pipes to not have twisting tensions on them. This is particularly important if you are using a glass container or aquarium for the sump. Bending and twisting forces on the glass can cause it to break when filled with water. Do not rush this process as you will be more likely to make mistakes.
Glue the parts of the sump together carefully. Take apart the dry-fit a piece at a time and glue everything into place. Again, do this carefully.
Wait for all the glue to dry and cure. This can take 48 hours or more. If you fill the sump with water before the glue has a chance to cure, the parts could come undone and the glue may leech into the water, poisoning the fish.
Fill the sump with salt water. You will need water in the sump to start the return pump and to start the circulation between the display aquarium. Check carefully for leaks before turning any pumps on.
Add the living organisms that will create the refugium. You may have to adjust the water level after adding rocks, sand, and animals. Remember to properly acclimate all living things to the aquarium water; this includes things like live rock and live sand.
Testing the System
Turn on the return pump. Be on your guard for sudden leaks and breakages. Be ready to turn off the power quickly if something goes wrong. If water is flowing from the display aquarium, to the sump, then back into the aquarium, then everything is likely working properly. Let this run for several hours, or even days, to be absolutely certain it is water tight and structurally sound. Check it frequently for small leaks. If you find leaks, turn the pump off and plug the holes, which may require draining the water from the sump.
Simulate a power outage by cutting the power to the entire system. You can do this by simply unplugging everything, including any pumps and powerheads in the display aquarium. You want to make sure the water stops flowing. Sometimes the pipes returning the water to the aquarium can create a siphon that sucks the water from the display into the sump, flooding the floor. To protect against this you can use anti-siphon valves and place the outlet of the return pipes near the surface of the water in the display aquarium. Additionally, always leave some room in the sump for a short siphon effect.
Simulate the power returning by starting everything at once. After a power outage, most devices will still be in the "on" position; when power is restored the devices will turn on suddenly. Sometimes this can cause problems. A common issue is when the return pump drains the water from the sump faster than the water can be replenished. When this happens, the pump runs dry, which can ruin the pump and possibly pose a fire hazard.