All Systems Go
There are many pieces of equipment that can be considered part of a filtration system, and most customers could use a system upgrade in their tanks.
The easiest equipment upgrade to sell a customer is in the area of filtration. Virtually no one has enough filtration for their tank, unless they keep a very low bioload. For example, the typical overflow power filter that is rated for 55 gallons only succeeds in cleaning one end of the aquarium really well. The other part of the tank is getting short-changed, unless a second filter of comparable size is added.
There are many pieces of equipment that fall in the realm of “filtration,” including those that enable the process, such as air pumps.
Pumps are integral parts of virtually every filter, whether they pump water or air. A re-circulating pump located inside an aquarium is not a filter in and of itself, unless the intake has a sponge over it to prevent unwanted debris from entering the pump. It is, however, a filter enabler and can be placed in an aisle marked “Filtration Equipment” with no pause for regret.
A Customer’s System
Filtration systems for customers are usually quite simple unless they are maintaining reef tanks. My pet peeve with reef enthusiasts is when they cram a sump with an over-sized protein skimmer, a UV-sterilizer, a refugium and a biotower. If this much equipment is necessary, it’s best to invest in a two-sump system.
When appearance is not a major concern, it’s perfectly acceptable to have a protein skimmer and UV-sterilizer hanging from a tank lip. The sump can be left strictly for biofiltration and/or the refugium. Also, I believe that as good as a wet/dry sump may be, no marine tank is complete without an overflow power filter for mechanical filtration. The amount of debris this filter can trap (even in a reef tank) is astounding.
A filter system that slows down as it becomes dirty is definitely a positive feature, as long as people are paying attention to the flow rate. All too often, the return is placed under water, so it is difficult to detect any subtle diminution of flow. Water returns should (at the very least) break the water’s surface, so they are visible. With an overflow filter, the flow is quite evident at a glance, as is the condition of the filter materials. If biowheels are being used, it’s important that they do not slow down as the filter becomes dirty. If anything, they need to work more efficiently as the filter gets dirtier.
I always encourage customers to review their filtration options on a regular basis. If a retailer carries specific filters, stock the expendable materials that are proprietary to these brands. They should be side by side on the shelf.
A store’s System
Over the years, I have put together quite a few in-store filtration systems, and experience is certainly a good teacher when it comes to such endeavors.
Let’s start with the placement of the overflow inside a tank. Standard positioning is in or near a corner, but this is a mistake for several reasons. First, boxes near a corner create a narrow “dead” space where fish can hide and are hard to catch or even see. Boxes in corners are okay, but they tend to filter one side of the tank much better than the other if there is only one. Overflows should be located in the center of a tank with a bifurcated return pointing directly at the front glass. This will direct the water flow to both sides of the tank. In order to increase water circulation and add valuable dissolved oxygen to the water, there should be an air stone in each corner of the tank.
It is inevitable that a central filtration system will need to be cut off periodically for maintenance. When this happens, the dual aeration in each tank will keep water circulating and reduce stress on the fish. This failsafe will become a necessity when a tank needs to be taken off-line due to disease. Tanks under treatment must be isolated from the central system so they can receive specialized regimes of medication.
What about the location of the reservoir that serves as the central “dump” point for water coming from the tanks? It would be convenient for this to be located near the tanks it services, but this is rarely possible, and having such an unsightly piece of equipment on public display can only detract from the ambiance of the fish department.
All system sumps should be located out of public sight, preferably behind a wall or curtain. Automatic fill valves are mandatory, as are float cut-off valves. These can easily be installed using equipment common to the aquaculture industry or the lawn sprinkler business.
Somewhere near the central sump, there should be a large commercial-grade heater to provide whatever temperature a retailer deems necessary. If some aquariums require higher water temperatures than the rest (such as these housing discus or brackish-water fish), add individual heaters to those tanks. Maintaining a constant even temperature is the best way to prevent outbreaks of disease.
When building a central system, remember that water flows downhill, so tank drains should always have a minimum slope that starts at the point furthest from the sump and gradually increases nearer to the sump. This ensures proper drainage (in one direction) and no water backups. As water enters the sump, it should be unrestricted and free-flowing until it reaches the point where mechanical filtration occurs. This is best accomplished by pulling the unfiltered water through a micron-filter chamber with the aid of a pump.
After leaving this area, the water should trickle over biomaterial, where chemical impurities are removed. Then, a percentage of the treated water can be diverted through a UV-sterilizer to be further cleansed. Finally, a large pump should return the water to lines below the tanks, where it is then forced upward and into the tanks themselves.
While water should always flow into the overflow box and downward, there is no reason why it cannot be returned above the tanks. This method may work best in some applications, but it will definitely present some décor challenges, since pipes above tanks are unsightly. From my perspective, the only objects that need to be visible above the tanks tops are the two small air lines dropping into the back corners of each tank.
If a retailer is going to vary the size of the tanks in a fish display, try to keep same-size aquariums on their own systems–it would be unreasonable to have 20-gallon tanks on a system with 75-gallon tanks. One small-tank system and one large-tank system is best. Plus, a variety of tank sizes will inspire customers to purchase a variety of tank sizes. Keep this in mind when designing a tank layout.
Edward C. Taylor has been in the pet industry for over 30 years as a retailer, live fish importer & wholesaler, & fish-hatchery manager.