The following are ideas for using an existing aquarium as a sump. The decision must be made as to whether you are going to use plastic or glass as the baffles. If you opt for glass I would recommend that you have a window place do the cutting for you. It is fairly cheap and the work will get done correctly. If you decide to use plastic you can use 1/8" Acrylite sheeting for the baffles and I would recommend using some sort of bracing between the baffles as the acrylic is quite flexible and will bow in the middle of the baffle. The cutting of the acrylic is very easy with a cheap disposable acrylic scoring blade available at hardware stores that carry the sheet plastic. Look in the window section.
Here is a list of tools that will help facilitate the retro-construction of an existing glass aquarium into a sump configuration:
- Drill motor with a hole saw and drill bits
- Files and sandpaper (wood files will suffice)
- Caulking gun
- Acrylic scoring tool
- Marking pen
If you are considering using the sump with a refugium incorporated, you may want to consider using some holes in the baffle nearest the return side and the baffle between the refugium and the return to help the water flow through the refugium. Remember that you will have critters in the refugium so you will want to keep them from getting into the return pump. I used some vinyl screening over the holes to discourage the critters from getting over the baffle and becoming fish food. Snails get over there anyway but if the pump has a screen over the input they usually do some clean up and then head back into the refugium. The diagram on page one is of a 20gal with a refugium. These holes can be drilled in glass but I do not recommend it without the proper drill bits!!
This is a list of materials for this project. Both designs, whether glass or acrylic baffles are used, will use the following:
- Silicone caulking appropriate for aquariums (aquarium silicone can be used or any other that is 100% pure silicone rubber and no other additives)
- 3 pieces of acrylic sheeting or glass pieces the same width as the interior width of the aquarium and 12" in height
- 2 pieces of acrylic 12" x 3" (this is for the input box, if you use glass you can use silicone to put it together, if you are using acrylic you will need a tube of Weldon #16 to glue the two pieces together)
- For the Refugium design, enough substrate material for 4 inch depth of substrate
- A 1" x 6" block of wood