Keep It Simple
Keep It Simple
Here are some suggestions on your sump/refugium design:
• Intake Compartment. With an external skimmer, you do not need a large intake compartment. My hang-on-tank skimmer only uses a 4†wide intake compartment.
• Refuge Compartment. For nitrate export, I recommend macro algae such as chaetomorpha. A DSB must be large to be effective so I keep my DSB in my display aquarium. This means you can simplify your baffles. For example, you only need one baffle between your intake and refuge compartments and water should flow underneath that baffle through the media holder. If the media is clogged, water can flow over the baffle.
• Lighting. I would not make the refuge compartment much wider than the PC light fixture. This fixture should rest directly on a 1/8†thick tempered glass cover. A Plexiglas cover will warp. A fixture with “legs†is unstable and wastes light.
• Constant Water Level. Only one baffle is needed to maintain a constant water level for your skimmer and refuge. I have only two baffles in my tank. Water flows underneath the first baffle to the refuge compartment but over the second baffle to the return compartment. This second baffle is the shorter one and sets the water level for both the intake and refuge compartments.
• Filter. To keep algae from spilling into the return compartment, I use a tall mesh tank divider that is propped up against a baffle. If your tank is made of Plexiglas, you may use a baffle with vertical slits or holes along the top. Alternatively, you may try placing bio-balls between two baffles. I don't see a need for three consecutive baffles.
• Return Compartment. Make this the largest compartment so you can use it for water changes. When making water changes, I shut off my pump and use my return compartment to mix the salt and to heat the solution before turning the pump back on. My return compartment occupies two-thirds of the tank. If it is too small, you are always topping it off to avoid running the pump dry. Placing the pump outside the tank is definitely the way to go. Don't forget a water level sensor to shut off the pump. In the cover over the return compartment, you can install a fan to cool the tank. My fan & heater are hooked to a 2-way controller.