In Wall Reef Aquarium

How would you design an in-wall reef aquarium so that a chiller would not be needed? It requires a bit of improvisation, but I accomplished this for a new client.

In July 2011, I received a phone call from a lady who needed me to move the contents of her 90-gallon, in-wall reef aquarium to a free-standing, 120-gallon aquarium in her new home. The gentleman who bought her old house requested an estimate for bringing the 90-gallon back into commission as a reef aquarium. The tank wasn't big, so I wanted to make sure that I made up for this by equipping it with great filtration and very bright lighting, all without causing too much heat to build up inside the cabinetry.

In Wall Reef Aquarium

In many cases, a chiller would be used to make certain the water temperature does not exceed 80° to 82°F, but not only was there zero space to add a chiller, it is also a huge mistake to put a chiller in a tight, enclosed, poorly ventilated space. A chiller dumps the heat that it removes to cool the water down, just like a window air conditioner, so it will seriously heat up the air in the cabinet. Also, the cooler the air it's allowed to draw in, the more efficiently it will cool the water.

Lighting

Right away I knew I was going to use LED lighting on this system. LEDs have come a long way since even a couple of years ago, and using T5 fluorescents or metal halides wouldn't have worked because too much heat would have been created inside the cabinetry. LEDs do produce some heat, but much less than either of the aforementioned light sources. When left on for an hour, a 150-watt metal halide bulb would burn your skin if touched, T5 fluorescents would be uncomfortably hot, and LEDs would only be warm to the touch.

There was already a bathroom exhaust fan installed in the ceiling inside of the cabinetry, which is great for removing lingering heat and humidity. Remember that the cooler you keep the area around an LED fixture, the longer you can expect to have them around functioning properly. When I called in to order the LED fixtures I was going to use, the manufacturer alerted me that a second-generation version was coming out that was brighter and would actually cost a little less. Unfortunately, it wouldn't be ready to ship for two months, I informed the new client about this and got him to see the virtue of being patient for this lighting system. Since I usually want the system to run for a month or so anyway before adding corals and other livestock, we could afford to wait for the lights.

Filtration

The former homeowner took all the filtration in the move, but that was fine because we had decided to upgrade anyway. For a year prior to setting up this reef system, I had been slowly adding solid carbon dosing to my clients' saltwater fish-only and reef systems to great effect. Solid carbon dosing is a method by which biodegradable plastic-like pellets are fluidized in a media reactor. The material the pellets are made from acts as both food source and colonizing surface for beneficial bacteria that consume nitrate and phosphate on a 1:1 basis.

It is important to place the effluent from the media reactor that you are using to fluidize the bio-pellets close to the intake of a protein skimmer. The bacteria are sloughed off of the surfaces of the pellets as they collide and are easily picked up by the skimmer, thus removing them, along with the nitrate and phosphate they utilized from the system.

Choosing an external main pump in this situation was easy, since it is very well known that submersible pumps transfer much more heat to the aquarium water than do those that are mounted outside of the sump (a sump is a glass or acrylic tank that sits underneath the aquarium and houses all the filtration). I sized the main pump, choosing one that was pressure rated rather than volume rated.

Electric shutter exhaust fan