Reefkeeping 101 -
Tank Selection and Placement

Last month we left off talking about water, and I want to add just a little more to that topic. Using Britta pitchers and/or tap water filters to provide water to marine aquaria is frequently brought up on Reef Central forums as a possible substitute for using an RO/DI. Well, if your reef is to be housed in a mayonnaise jar, then you possibly can use these substitutes. For most anything else, they will eat up the bucks for sure. Why? They may have some DI resin in the cartridge, along with some activated carbon and a particulate filter. The problem is that only a couple of ounces fit into such a tiny filter. Even worse, they have no RO filter, so that tiny amount of DI resin must remove everything from the water. As I explained in last month’s column, the RO section does 98% of the work removing substances from the tap water, and that makes the RO/DI last 50 times as long as it would if the DI had to do all the removal by itself. The same holds true with a tap filter. The small amount of DI resin is quickly saturated and must be replaced often. That means replacing the entire filter, which costs $12-$24 each. To fill even a 55-gallon tank would take about half a dozen, about the same cost that a low-end RO/DI costs. I’m well aware that many new reefkeepers are on limited budgets, so I'll tell you right now that the RO/DI is far more economical in the long run.

Well, let’s move off water (we will return to it) and find something to put that water into.Let’s consider size first. For a freshwater system almost any tank large enough to hold the fish is fine. You can even fit some pretty large fish, such as Oscars, into a tank as small as 55 gallons. Saltwater fish need far more room; they tend to be more active than marine fish, and some specimens can grow twice as large as a full-grown Oscar. This means that, unless you plan to house mainly corals and a couple of small fish, saltwater tanks need to be larger than freshwater tanks. Another point here is the larger the tank, the more stable it is. Water parameters such as temperature and water chemistry are much less likely to change drastically in a large tank than in a small one. For newbies, I always recommend a tank of around 100 gallons as a starter, and bigger is better, especially if you plan to keep any large fish. Before selecting a tank, though, let’s see where you are going to put it.

We want to be careful that the 5000-gallon, reef-ready tank is going to be comfortable in its new home, and that the house has the utilities needed to support it (possibly a nuclear power plant in the basement!). Now, a more realistic 100-gallon tank is still going to weigh in at close to half a ton. That’s a lot of weight! In a modern house the floors are usually constructed, to comply with the building code, to easily support a 100-gallon tank and, with some modification, maybe even a 5000-gallon. Don’t forget that a good stand spreads the weight over a fairly large area. Do be careful to ensure that the stand has support all around it, and avoid four- or six-legged stands with a large tank. Old homes may be a different story. Building codes may have been very lax or non-existent when those homes were built, and furniture such as giant screen TV entertainment centers or a 20 cubic foot freezer, holding a side of beef, were things of dreams only. Also, just like the old WaterKeeper, their structure lost something with age. In cases like this it may be wise to consult a structural engineer before adding “Mega Tank” to the third floor.

One other issue is having a tank in a multi-story building. Although the first floor may be fine, a really large tank on an upper floor can turn out to be a nightmare for servicing during water changes or, Lord forbid, if the tank overflows, dripping down on that collection of Monets on the floor below. Some apartment leases also limit the size of aquariums.

Assuming that the floor will support a large tank, you need to look at your electrical service. The lighting alone for a 300-gallon system consumes 1500-2400 watts of juice. For a large tank, estimate that it will take about 10 watts per gallon to run everything. This means that you may need to place the lights and equipment on a circuit of their own, perhaps two, because a single 20 amp circuit will not support 3000 watts. This can be a considerable expense unless you happen to be an electrician.

While on the topic of electricity, here is another essential thing to know, and this one can save your life. Saltwater is far more electrically conductive than freshwater. Most tanks have lights, pumps, heaters, etc. all pulling current and all creating possible shock hazards. A simple device called a Ground Fault Circuit Interrupter (GFCI) can stop those shocks before they can kill. It senses when current is no longer running in the proper circuit and, instead, is flowing directly to ground. When that happens, it trips the circuit just like the home circuit breaker does when the load is too great. In fact, some circuit breakers include a GFCI that replaces the normal breakers in the fuse box. Another type replaces only wall receptacles, in case you don’t need to protect a whole circuit. If you do install a wall outlet GFCI, any other outlets down the line from the GFCI outlet will also be protected. To check whether they are, plug something into the outlet in question and trip the GFCI outlet by pushing the TEST button. If what you plugged in turns off, it is a protected outlet. Finally, for you electrically-challenged newbies, some GFCIs work off plug-in power strips. Please do not confuse surge protector power strips with GFCIs; they are not the same. If in doubt, a GFCI has both a TEST button and a RESET button on the strip. A power strip GFCI does not protect other outlets like a wall receptacle type does. Most homes have a GFCI wall outlet in the bathroom and kitchen. PLEASE make sure that all your saltwater equipment is GFCI protected! They are inexpensive insurance for your life and your family.

Another important point to look at is the other essential utility - water. You don't really want a first floor, kitchen-mounted RO/DI unit to do a water change on a tank located on the third floor. Well, maybe some of you Marines do. Also, where will water drain? It is easier if there is some way you can plumb things directly to a drain. WaterKeeper is lazy, and avoids carrying water from place to place.

Take a look around and ask, is the location away from heat vents or radiators? They will play havoc with your system’s temperature control. Will this location get direct sunlight from the windows? Direct sunlight isn't bad for the tank and doesn't promote algae growth any more than artificial lighting does. In fact, it may really be a benefit. However, it can heat up the water really fast, and some people end up buying an expensive chiller to keep things cool when simply choosing a better location for the tank would have done the same job. High traffic areas are also undesirable. If people are constantly walking past the tank, some fish go into hiding in the rockwork, barely ever to be seen. If you can spare a closet area next to the tank’s location, it is a great place to put a remote sump and tank equipment. So is having a sump in the basement. It is far easier to work on things standing up than crawling under a tank stand and working in the confined space it offers.

Okay, we have the right spot and an idea of how big a tank will fit in there. We still have some decisions to make. One of those is acrylic versus glass. Here are some thoughts I had on this subject in the past and still believe they are generally true.

As any manufacturer of acrylic tanks will tell you, acrylic tanks beat glass tanks hands down. Acrylic tanks:

  • Weigh less than glass
  • Are stronger than glass
  • Appear more transparent than glass
  • Have no seams to leak
  • Are much easier to drill than glass
  • Can be molded into unusual shapes
  • Are better thermal insulators than glass
  • Help preserve the world’s ever-dwindling supply of silicone

With all these merits, we have barely scratched the surface of the marvels of an acrylic tank. Well, hush my mouth; did I say "scratched"? Sadly, acrylic tanks are scratched more easily than a three-legged horse in the Kentucky Derby; easily enough that this flaw outweighs most of their other positive qualities.

Sure, you say, "I'll be really, really careful," but the sad truth is that even the most carefully managed acrylic tank is going to scratch over time. We all think about major scratches that occur when a piece of live rock is dragged across the acrylic’s surface, but most of the scratching is far more subtle. Particles of fine sand get sucked up by powerheads and propelled into the sides of the tank. Using a magnetic scraper crushes calcium deposits contained in coralline algae into a fine abrasive powder. Kids slide their silver teething rings across the outside of the tank.

Over time, micro scratches in the tank give it a dull, cloudy appearance. One of the main reasons for choosing acrylic is its clarity, and this haze does not enhance that image. Also, the glass aquarium manufacturers are not blind to the fact that standard glass is just not as pleasing to the eye as acrylic. To counter this, they now offer tanks made from low iron float glasses. With brand names such as Starphire™, OptiWhite™ and UltraWhite™, these tanks avoid the greenish cast that standard glass imparts due to its iron content. This really levels the playing field.

I've heard mixed results on using buffing kits to remove scratches from acrylic tanks. Some people believe that all they do is trade larger scratches for lots of smaller, micro scratches, creating an overall haze. Touring various threads on Reef Central, you find many acrylic tank owners saying that their next tank will be glass. Not so with glass tank owners, who rarely want to change.

In addition, some of the other arguments against glass are also somewhat overstated. A 100-gallon glass tank, when empty, weighs about 180 lbs., and the acrylic only about 80-85 lbs. Still, when both are full of water, they end up weighing over a half-ton, so a hundred pounds here or there is not a big issue. Glass tanks do have seams, but leakage is unlikely in a quality tank, and usually occurs when you do something foolish, such as trying to move a full tank. The silicone in used glass tanks that have been stored dry can also degrade over time, but they can be repaired. On small tanks, those 20 gallons and under, the acrylic's insulating ability will help to control temperature swings. In larger tanks this effect becomes fairly moot as the water itself provides thermal stability.

True, standard glass tanks are cheap, but if you are considering acrylic, you probably can afford to get a low-iron glass tank. It is worth the extra money and really doesn't cost much more than acrylic.

Overall, I tend to be biased toward glass.

Now, I am sure that some of you will chose acrylic, especially if you plan on an exotically shaped tank. You can't have those with glass tanks. What's that? Well, you tell your glass blower friend to make you a 150-gallon glass tank shaped like the Pillsbury Doughboy, and tell us how it works out. Brother! Anyway, the choice is yours, and I will let you decide.

One other thing while we are talking about tank selection and unusually shaped tanks. Height is always an issue, and I caution novices not to get excited about very tall tanks. They may be aesthetically pleasing, but can be a challenge to light. I will be talking about lighting pretty soon, but let me give you this now. A three-foot deep tank requires almost nine times as much illumination to provide the same level that it does for a one-foot deep tank. That can drastically impact the lighting costs.

You are going to need a stand in most cases, and there is nothing wrong (most of the time) with choosing one that comes with the tank. Just make sure that you can access it from the front if it is to be up against a wall. Also, check that it has enough room under it to fit a sump if you are going to have one under the stand. The main drawback of these combination packages is that they often include a hood or canopy that, as I will explain, may not be optimal for a reef tank.

You can usually rely on manufactured stands made for aquariums to be able to support the tank they are designed to handle. If the tank is large, do not choose a stand with legs, but rather one that touches the floor at all points along its bottom edge. Such a configuration distributes the weight evenly across the floor. Be very, very careful to stay away from stands such as those carts that are made for TVs. My 32" HD set is heavy, weighing about 120 lbs. However, a 40-gallon tank would probably fit the stand, too, but would weigh just under 400 pounds, three times the weight of the TV. You can imagine what would happen when I filled that 40 with water and live rock. Another thing about using stands not made for an aquarium - never, ever let the tank extend beyond the stand's perimeter. If there is an overhang, the stress on the tank may be enough to fracture it. It is also nice to have a stand that is a little longer than the tank itself. This leaves a shelf on the side where you can place your tank maintenance items when working on the tank. It is far safer than placing things on the canopy, where they can accidentally fall into the tank.

I have noticed one trend here on Reef Central. We seem to have a whole gang of people who watch Norm Abram every week on The New Yankee Workshop. And, like Norm, they seem to have about every power tool that was ever manufactured. I'm sure I'm speaking to some of you right now, and that means--No Danged Store Bought Stand for Your Tank! I look around the DIY forum and some stands there look like they should be in a formal dining room at some palace. Well, gang, I have an electric screwdriver and that is it, so I will not dare to give you tips on building your own. If you do build your own, you may want to consult with some of the structural engineers that live over on our Reef Central DIY forum with your plans. I am sure your stand will be a work of art.

I mentioned before that with the complete aquarium package deals you also end up getting a hood or canopy that may or may not work for a reef tank. Let's talk briefly about this before winding it up for this article. Many of these package deals are still made with freshwater systems in mind. Usually, they are just a couple of fluorescent tubes mounted in a plastic hood with a low grade reflector over the tubes. For a reef you will want much better lighting than these systems offer. True, if you desire to have just reef fish and no corals, anemones and other photosynthetic invertebrates, then any hood will probably do. Some of these ready-made hoods may also be upgradeable with some DIY work. If you get one with four T-12 normal output (NO) fluorescents, just changing out the ballast to a very high output (VHO) electronic ballast will make it a reef type hood.

Okay, okay, I see you scratching your heads. T-12, NO, VHO, ballasts? Is that ballast like you have in a ship? You are right; we really need to define lighting terms before going on. At this point, then, I'll stop, because lighting is next month's featured topic. All of these issues will be explained as we tackle one of the more complicated and budget-eating issues for a new tank.

I know this is taking time and some of you question why a reef tank takes so long compared to the "buy it and stock it," freshwater tank. Well, many reefkeepers are also gardeners, and what did we do last month? Planted bulbs, that is what. It was October then, and those tulips won't be showing their heads around here until sometime in April or even May. That's a long time, but it is part of the hobby. A reef tank is like an underwater garden, and things take time. I usually figure that a new tank is still a "new tank" for the first year after it is set up. Novice reefkeepers need to take things slowly and give nature time to work her magic. It will pay off handsomely in the future.

One last thing - when I write these articles as part of a thread I can keep them interactive. Here they are not, but don't lose faith. I have placed a "sticky thread" at the top of the New to the Hobby Forum entitled "Newbie Corner Feedback," where you can post your questions or comments.

What? I'm doing this in Reefkeeping Magazine because when Skip, the Reefkeeping editor, gets done with my stuff it looks great; a lot nicer than it does when I say it in a thread post. This way you can print it out and put it in a binder.

;Huh? What for? To use as toilet paper in case you run out, okay?

If you have any questions or comments about this article, please visit this thread in the New to the Hobby forum on Reef Central.

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Reefkeeping 101 - Tank Selection and Placement by Tom Murphy (aka WaterKeeper) -