Most people who keep marine aquariums want two things, first and foremost for their critters to flourish and second – a bigger tank. Now don’t lie to yourself you know its true, its normally just a matter of time till you feel this need to go BIG. The problem with going BIG is that most people do not take the necessary time to think about what having a larger tank means in terms of both proper setup as well as costs (both emotional and financial). The rest of this article will discuss some of these BIG issues and some steps to take before you set up that dream tank or yours.

First let us define what is meant by BIG tank, this is of course all relative but here a BIG tank is typically anything over 200 gallons. For our discussion purposes here we will also assume the worse case scenario of our BIG tank being a reef tank, a large fish only tank is still quite a handful and all the things we discuss are applicable but just not to the same degree of complexity.

The normal first step someone takes in contemplating setting up a large tank is how much space do I have and how big a tank can I fit. The problem is, this is where a lot of people stop before going out and acquiring their BIG tank, its only after they start trying to install the new tank that they realize that maybe this is not going to be quite as simple as they thought. You will find that taking additional time planning before you buy and setup your large tank is well worth it and likely to save you both significant pain and money later. With this thought in mind lets cover some of the areas where a little planning can be a big plus.

When deciding on a location for your large tank as well as its actual selection you need to consider the following:

1. Will the floor support the necessary weight? Larger tanks are often taller as well and taller tanks, when filled, are much heavier than shorter tanks. A 36" tall tank will weight over 200 lbs/ft2 whereas floor code for most residential buildings is for a rated average loading of 40 lbs/ft2. Unless you have a slab concrete floor you probably want to place a big tank along a load bearing wall (i.e., wall along the foundation or known to have sufficient support capability) and not in the middle of the room. If at all uncertain about structural design of your floor, consult a contractor or other construction professional to help you out. A rough estimate of a reef tanks total setup weight can be made by multiplying the tanks rated gallons by about 11.5 lbs/gallon (varies with the amount/type of rock/substrate used and does not include stand, canopy or any sump/equipment which may add an additional 15-25% to total weight).

2. Tank construction? There are several different designs and materials that can be used for tank construction, each with their own pros and cons. The table #1 lists some of the more common options (and one not so common) and their advantages and disadvantages. Unless you or someone you know are capable constructing a plywood/fiberglass custom tank then acrylic is probably best material for larger tanks such as we are discussing here.

Table #1

Tank construction	Advantages	Disadvantages
Acrylic	Lighter weight, good clarity, easy to plumb, more readily available in larger sizes. Better thermal insulator than glass (better at stabilizing internal water temperature).	Scratches easier, smaller top openings due to structural requirements.
Glass	Less prone to scratching, typically larger top openings.	Heavier construction, less clarity unless special glass is use (much more expensive), more prone to breakage, difficult to plumb, poorer thermal insulator and more difficult to find in larger sizes.
Plywood/fiberglass (using glass viewing pane(s))	Possible DIY for lower cost. Better insulation on the non-glass sides and lighter than all glass tank. More flexibility in tank shapes.	More difficult to obtain unless willing to DIY. Works best if tank is built into wall or large cabinet.

 

3. Stand construction? As with the floor you need to make sure any stand you plan on using for the tank is capable of supporting its fully loaded weight by a significant margin (need to allow for dynamic issues such as mild earthquakes, someone climbing/leaning on it, etc.). If you plan to house most of your equipment and sump under the tank then you need to make sure that the stand provides adequate space as well as access to this equipment for repair or maintenance. It is especially important that you make sure that you have openings in the stand large enough to allow insertion of the sump if that is were it is to be located.

4. Proper access to all areas of tank? The cardinal rule is: "If maintenance is difficult to do it will not get done". Make sure that all areas of the tank that you need to get to for maintenance (or attend to specimens) are easily accessible or can readily be made so. Especially for a large tank - make sure that all pumps, outlets, filters and especially the sides of the tank that need to be cleaned are readily accessible. One of the keys to making the tank accessible for cleaning as well as getting to specimens is to have a canopy or lighting system that is easily removed or constructed so as to not hinder access by allowing it to be opened or hinged in some fashion.

5. Power access - A large reef tank requires a lot of power unless you use natural lighting and even then it can be substantial. A 240 gallon reef tank can use 20- 30 amps peak power depending on configuration, which means that you need at least two dedicated breaker/fuse circuits of at least 15-20 amps each. Significantly more than 240 gallons and you might need three or more. Try to estimate what your peak current requirements will be to see how many power circuits you might need (remember to add any other items that might be plugged into these circuits even if they are not aquarium related). It is highly recommended that you do not load any one electrical circuit more than about 75-80% of its maximum to give adequate safety margin (e.g., do not have more than about 12 amps peak operating on a 15 amp circuit). Unless you are fortunate in your current house wiring at the selected location you will likely need to add additional circuits and wiring to support a much larger tank.

6. Heating and cooling - Equipment to support a large reef tank can generate a lot of heat (especially using metal halide lighting) and depending on tank location (try to avoid placing tank so it receives direct sunlight), cooling, even with a chiller, can be a problem. If you can remotely locate the chiller outside in a cool location (you do not want the chiller subjected to full sunlight as they can fail if their ambient air temperature runs much above 95° F) this can help reduce some of the room/tank heating but between the lighting and pumps required for a large tank you will still have plenty. If your house is air conditioned this will help but if not, try to have a significant number of fans strategically placed to help cool the tank through evaporation. It is also recommended that you have your lighting system set up with a controller that can shut all or a part of it off if the tank temp gets too high (you can also have equipment such as skimmer pumps set to turn off if temp is too high as these pumps can be fairly large depending on skimmer design). Heating a tank during cold nights is much easier, see the equipment section for more details.

7. Evaporation rate - A large tank evaporates a significant amount of water on a daily basis (likely several gallons) especially if you are using fans to help keep the tank cool. Yes, you can reduce this rate of evaporation if you seal much of the tank but then you will have more difficulty cooling the tank as well as possible problems with maintaining high oxygen levels in the water. It is highly recommended to have some sort of automated freshwater top off system planned and plumbed unless you really like having to add this much make up water to the tank every day or two.

8. Tank overflows -A larger tank needs more overflow area/capacity to handle the larger flow rates required as well as a safety margin should a portion of it become clogged. It is also recommended that you use multiple overflows to reduce the possibility that a single clogged overflow could cause major tank problems. And while it is possible to increase an overflows capacity by increasing slot depths or hole diameters (depending on your overflow type) keep in mind that more of the tank will drain into the sump during power outages. This means that you need to make sure your sump can handle the additional water without overflowing itself and even more important that you do not have any specimens located high enough in the tank that they will be left high and dry during said power outage.

9. Tank leveling - While important to most any tank, leveling is even more important to make sure that a large tank is properly set up. Most large tanks have multiple overflows returning to the sump and if not properly leveled you may find that one or more of the overflows will be overloaded while others are under utilized. Also additional mechanical stresses can be placed on the tank itself if not properly leveled possibly leading to premature failure of tank (definitely a bad thing).

Reliability and safety concerns:

Once you have your tank sized and located there are other important issues that you need to consider, primarily associated with safety and reliability.

1. Redundancy - Why is redundancy important you say? You will by the time you are done setting up a large tank have a significant amount of both time and money invested. The last thing you want to have happen is for your large tank to crash because of some failure of one piece of equipment or a blown breaker/fuse. By having duplicate systems such as heaters, circulation pumps (both within the tank and well as from sump) you greatly minimize the likelihood of one piece of equipment failure causing short term (< week) tank catastrophes. Also, since you will likely have to run multiple electrical circuits to power your mega tank anyway you can strategically group various pieces of equipment on different circuits so if one of the breakers/fuses does blow it will not cause an immediate problem in the tank.

2. Electrical safety - As mentioned before a large tank uses a lot of electrical power and thus is even more at risk due to electrical failures such as shorts or wiring problems. It is a good idea to use Ground Fault Interrupter (GFI) circuits on many of the major electrical components so that if there are problems with electrical shorts these pieces of electrical gear will be shut down to prevent harm to both your tank and yourself. Do not use a single GFI on multiple pieces of equipment unless you are confident that a shutting down of all of this grouping will not harm the tank in the short term. Also be careful when using GFI’s on electrically noisy pieces of equipment such as electronic ballasts as they may be more prone to prematurely trip during normal on/off cycles when operating these. Always try to place power outlets so that they will stay dry (placing a power strip on the bottom of your stand next to the sump is not a good idea).

3. Power cycling test - Another safety tip that not just applies to large aquariums but one of any size is to make sure you do a power off/on cycle test with your tank. This means to shut the whole tank’s electrical power off (simulating a power outage) and verify that you do not have any problems with overflowing of sumps, tank drainings or any problems with systems coming back online properly when the power is turned back on.

4. Securing the tank? - Depending on the height of the tank relative to its footprint (i.e., a tall narrow tank) you may also want to secure the tank to a wall or other fixed structure to prevent it from being tipped over accidentally. This can be especially important if you live in earthquake country such as I do but having a tank in a garage in which you park a car can also lead to some interesting scenarios.

5. Back up power? - Here is the ultimate form of added reliability but can be very costly and may not even work when most needed depending on the situation. The most common form this sort of power back up takes is one in which you have a gas powered electrical generator that can supply all or a portion of your tanks power requirements for a limit amount of time. The problem with this approach is that most of the generators typically used require that they be started manually which means that if you are not home during a power outage or sleeping at the time it happens you may not find out about it till its too late. The more sophisticated (read more expensive) form of power back up is one that is self starting when the power fails. A fancy system like this will normally cost several thousand dollars but may be worth it to you when you consider the investment in time and money your BIG tank will ultimately take. Since the most serious failure mode with a power outage is lack of water circulation, a more cost effective solution to this problem is to have just a few internal circulation pumps on an automated back-up system. Computer UPS units are designed to keep computers up and running during power outages automatically to allow controlled shut down of these systems. And while it is true that these systems normally only are rated for a 15-30 minuets of operation, if you significantly reduce the load (i.e., power) that one of these units have to supply relative to its rated maximum power capability then they will operate for several hours. Brand new, these computer back up units are fairly expensive but there is a large used market for these (check out e-bay) and a used one can be had at a fraction of what a new one runs. Typically try to size one of these UPS units to be about 10-20X the maximum power capability of the circulation pumps used to get several hours of operation. I like to try to get 12 hours if possible, longer time than this and then other factors such as temperature control and such may also start to become a factor and other steps may need to be taken to prevent damage to the tank inhabitants. For a large tank it may be more cost effective to get a couple of smaller UPS units rather than a single large one.

A BIG tank necessitates bigger or more associated equipment to operate it, selection of this equipment can be as important as the selection of the tank itself. The additional equipment can be split up into the following groups: lighting, circulation, temperature control, water chemistry control and sump. You might also wish to consider timers and/or computer controls as a separate equipment group as well.

1. Lighting - Larger tanks need larger lighting systems, not only because they are larger in surface area but also because they tend to be deeper as well. If you recall your basic lighting theory for tanks - a deeper tank requires more light to maintain a given light intensity at its bottom than a shallower tank. Figure about 40-125 watts per square foot of tank surface area depending on what your goals are and the depth of the tank. If you are trying to maintain SPS corals then you typically want a more intense lighting system, if keeping certain soft corals or a fish only tank, your requirements will likely be more moderate. With a large tank you also have the option of having part of the tank using lower light intensity than others to allow placement of different types of specimens in different areas of the tank. Larger light fixtures (i.e., higher wattage) tend to be more efficient than smaller but you tend to lose some of your flexibility in terms of light control over different areas or times as well as the added reliability that redundancy brings with a larger number of smaller fixtures. The most flexible lighting system is often a pendent based system in which you can easily adjust the height of each fixture to control the light intensity at any given location in the tank (also good for photo adapting specimens). This pendent lighting configuration also has the advantage that it allows ready access to the top of the tank for maintenance purposes. The down side is that the pendent "look" may not fit your décor requirements.

2. Circulation - Most people tend to have too little water movement in their tanks and with larger tanks this can be even more apparent. Not only is water circulation important to water chemistry control (removal of wastes and replenishment of oxygen/nutrients) but it also helps minimize accumulation of debris on specimens while stimulating them into feeding. The paths the water circulation takes are just as important if not more so than the amount of circulation. Try to avoid stagnate flow patterns (i.e., flows the same direction all the time) and make sure all parts of the tank are effected (avoid having dead spots in terms of flow patterns). The best way to achieve this kind of flow control (but by no means the only way) is to have several returns and/or power heads that run in different directions and at different times. Having several circulation pumps also helps reliability again with their inherent redundancy. To coordinate this array of circulation pumps some sort of pump timers or wave makers are recommended though other devices that change the water flow direction over time (e.g., rotating nozzles and their kin) are also viable alternatives or additions. You typically do not need a real high flow rate between the sump and the tank, just enough to allow proper temperature control and efficient operation of any filter systems operating from the sump. Probably a sump to tank turn over rate of 2-3X an hour is adequate for most systems (e.g., 600-900 gallons/hour for a 300 gallon system). The rest of the tank circulation can be done with internal/closed circulation systems (this does not just have to be power heads, you can also use external pumps that take water from one part of the tank and return it to another). The actual level of circulation in a tank will again depend on the livestock being kept. SPS corals tend to like higher flow rates while LPS corals a more moderate flow rate. By judiciously adjusting the various internal as well as external circulation units in a large tank you can tailor different sections of the tank for diverse specimens and thus keep things together that would not be possible in a smaller system.

3. Temperature control (cooling) - As mentioned before, a large reef tank can generate a lot of heat, which needs to be controlled or critters will suffer and in extreme cases die. Unless you live in a very moderate to cold climate, have whole house air conditioning, live in a wind tunnel or preferably some combination of the above you will likely need a chiller to control tank temperature. You may not need a chiller to operate very often but then all it takes is just one unusually hot day to have disastrous effects on a tank’s inhabitants (both personally as well as many friends have found this out the hard way). Sizing a chiller for a tank again depends on both the tank size and the delta temperature it has to operate with. This delta temperature refers to the maximum difference in temperature between the waters desired temperature and the ambient air temperature, the larger the delta temp the more work the chiller has to do to cool the water for a given size of tank. Table #2 gives the size of chiller (normally quoted in horse power) needed for a given delta temperature and tank size in gallons, figure flow rate through chiller to be about 2-3X tank gallons/hour. Any thing over ½ HP and you may wish to consider multiple smaller units again for the added reliability that redundancy brings.

1. Example: Assume the desired max tank temp for a 400 gallon tank is 80° F and expected max ambient air temp is 100° F, using the table for 20° F pull down and rounding up on tank size we get ¾ HP chiller required (or two ½ HP units?).

 

Chiller	Delta temperature pull down (degrees Fahrenheit)
(HP)	5	10	15	20	25	30	35	40
1/6	200	100	67	50	----	----	----	----
1/5	560	280	187	140	112	93	80	70
1/4	800	400	267	200	160	133	114	100
1/3	1000	500	333	250	200	167	143	125
1/2	1440	720	480	360	288	240	206	180
3/4	2600	1300	867	650	520	433	371	325
1	3360	1680	1120	840	672	560	480	420
1 1/2	5040	2520	1680	1260	1008	840	720	630
2	6720	3360	2240	1680	1344	1120	960	840
3	10080	5040	3360	2520	2016	1680	1440	1260
4	13440	6720	4480	3360	2688	2240	1920	1680
5	16800	8400	5600	4200	3360	2800	2400	2100
8	26880	13440	8960	6720	5376	4480	3840	3360
10	33600	16800	11200	8400	6720	5600	4800	4200
12	40320	20160	13440	10080	8064	6720	5760	5040
15	50400	25200	16800	12600	10080	8400	7200	6300

 

3. Temperature control (heating) - Heating is of course the flip side of this temperature control issue but is much easier (and cheaper) to accomplish than cooling. Resistive base aquarium water heaters are readily available in various wattages, again multiple smaller units are preferable to single large units for the improved reliability they provide. Figure about 60-75 watts/100 gallons for an acrylic tank (figure 3-4X this for a glass tank) to achieve a maximum 15° F increase in tank temperature above the temperature outside the tank.

Example: If for a 300 gallon tank you wish to maintain a minimum tank temperature of 75° F and the worse case cold ambient air temperature is expected to be 45° F the minimum total heater wattage will be (75-45)/15*75/100*300 = 450 watts, to give an additional safety margin (and since it does not cost much more) increase this by at least 33% or roughly 600 watts. Actual recommendations for this system are 3 X 200 watt heaters or 4 X 150 watt units.

4. Water Chemistry control - The primary goal with water chemistry control is to maintain stability, this means that parameters such as salinity, oxygen levels, temperature, alkalinity (PH), waste levels and trace elements need to be kept at their proper levels or at least within acceptable ranges. We’ve already discussed temperature control so we will concentrate on the other water chemistry parameters.

1. Oxygen levels: Oxygen levels can be among the easiest to maintain as long as adequate circulation exists in the tank and that areas for gas exchange are provided (i.e., no sealing the tank top unless other means are provided to allow adequate gas exchange). Overflows and skimmers also provide gas exchange to help keep oxygen levels at or near saturation levels.

2. Salinity: Maintaining salinity, while easy in theory can be more difficult in practice. It was mentioned in the first section that having an automated top off system for replacing water evaporation was highly recommended to reduce your workload and improve the stability of the salinity in the tank. The source of this water for this top off system should be treated to make it safe for use in the tank (i.e., filtered to remove any undesirable elements such as chlorine, nitrates, phosphates or any other chemicals that could harm the tank or its inhabitants). The most common means of achieving this filtering is through the use of a DeIonizer (DI), Reverse Osmosis unit (RO) or some combination of the two. Remember you will likely be adding several gallons of make up water a day to your large tank so size filter units and top off systems accordingly.

3. PH (alkalinity): The next most important chemistry parameter is PH and its maintenance is through having an adequate buffer system or high enough levels of alkalinity. A live sand bed of sufficient size can help with stabilizing alkalinity levels as it slowly dissolves in the tank but typically you need additional help with maintaining high alkalinity levels. You can achieve further alkalinity boosts through periodic addition of buffering chemicals but for a large tank this can be cumbersome so a system such as a CO2 calcium reactor is suggested. Through a device such as this, not only can you maintain high buffer/alkalinity levels but also increased calcium levels which help the growth of hard corals and coralline algae. Size of such a reactor will again depend on type and number of specimens being kept that use calcium (e.g., stony corals, clams, certain algae etc.) as well as the fish load and how much/often feeding is done to the tank (i.e., amount of potential wastes being added/generated which in turn drop alkalinity levels). Check with the reactor vendor’s specific recommendations as to sizing for your particular application.

4. Waste disposal: The next subject is that of waste removal, I’ve down played its importance here only because it is assume that you will be doing most of your waste removal/neutralization via established biological filters in the tank and/or sump (e.g., live rock, live sand, algae filters, etc.). It is often recommended that these biological filters be supplemented by additional chemical filters such as protein skimmers, activated charcoal and/or other similar filters. The primary purpose of these additional filters is to remove materials not normally handled by the biological filters or to act as fast reaction chemical filters to sudden changes in waste levels in the tank (biological filters normally require some time period to adjust to sudden changes in waste levels to fully handle). Actual filter units used and their size will depend on your bio-load in your tank (i.e., what percentage of your tank volume is living matter and how much you feed it) and of course the total volume of water in the system. Check with the specific filter vendor’s recommended sizes for your particular system. As some of these units can be quite large (especially skimmers) you need to make sure you have adequate space to place and operate them. As mentioned in the sump selection coming up having an adjacent equipment room and/or closet capable of holding these units is ideal. If you do not have this option then make sure that adequate space is available in the stand or adjacent to the tank itself, keeping in mind the need for periodic maintenance. One last comment on waste control in large tanks - one of the advantages to a large tank is its larger water volume so you should be less prone to significant changes in water chemistry due to decaying matter or introduction of new specimens unless the amount of decay or number of added specimens is correspondingly larger.

5. Trace elements: The last water chemistry concern is the most difficult to quantify and is that of trace elements. Trace elements used in reef tanks range from the previously mentioned calcium but can also include strontium, iodine, manganese and others. We will not try to cover the pros and cons of the various trace elements but concentrate on how to maintain them in a large tank. There are basically two ways of maintaining trace element levels in your tank (not necessarily mutually exclusive either) – water changes and dosing. Water change is the most straight forward method of trace element replacement but not necessarily the easiest or best. The trouble with relying on water changes is that it is cumbersome and not targeted. When you exchange water you are adding all the trace elements (at least all those present in your replacement water) where as you may really only need to add certain trace elements due to the rate at which they are used up in the tank (i.e., calcium may be used at a much higher rate than say iodine or iron). Dosing on the other hand can be more targeted by only adding those trace elements that you want and in more controlled quantities. A dosing system normally consists of a reservoir containing the source of the desired trace elements and a special pump that can dispense very small amount of liquid at a time called a dosing or metering pump. A system of this type can be independent of the rest of the tank or can be used in conjunction with the evaporation top-off system. The actual size of a dosing system is again depended on your specific requirements and size of system. You will likely have to experiment with dosing rates and supplement concentrations and then measure the levels of the specific trace elements in the tank using test kits or probes to see if it is correct.

 

5. Sump selection - Sumps can serve several functions - they help maintain the tanks proper level in conjunction with overflows by acting as a water reserve, they provide a convient location to operate various pieces of equipment from, without interference from tank inhabitants (e.g., filters, heaters, pumps, etc.) and last but not least they hold an additional volume of water to help dilute wastes generated from the tank’s inhabitants and thus enhance water chemistry stability. This last function, that of helping to dilute wastes, would tend to argue for a larger sump and if possible this is recommended. A sump sized to 20% or more of the main tanks volume is not at all unreasonable with 100% not unheard of. A larger sump can also be partitioned such that part of it could act as a refugium that could allow the growth of certain desirable organisms (plankton, copepods and other microorganisms) that could otherwise not be maintained in the main tank alone due to too many predators. When adjusting the water level in a sump make sure that it can accommodate any additional water that may flow back into it during power shut downs or outages (see power cycle test in first section). Locating a larger sump can be an issue as placing a large sump below the main tank may be difficult. The ideal situation is to have an adjacent room to the tank that you can use as an equipment room in which to locate not only the sump but also some of the other filters and pumps.

It should come as no great surprise that a large tank is both more expensive to setup as well as operate. A large tank can cost several thousands of dollars to set up, thousands more to stock and hundreds of dollars a month to operate. Yes, there are ways of reducing or minimizing this cost some but still expect to have to make a major investment. First lets do a rough estimate for an example tank and then see what we might do to reduce costs.

Lets say we wish to set up a 240 gallon reef tank that will need to support stony corals. This means that we will need a larger lighting system and a calcium reactor to properly support the desired critters. Below is listed the major pieces of equipment chosen for this system and approximate cost estimates for new units.

Before you run for the hills remember this is a worse case condition with all (well at least most) the bells and whistles. On the other hand this is only a moderately BIG tank and larger than this will scale costs accordingly. I mentioned before that there are things you can do to reduce costs and while we could trim here and there by choosing different equipment, the number one thing you can do to reduce costs significantly is to look for used equipment and tanks. A used tank and support equipment can cost 25-50% of new. The downside of used equipment is potentially reduced reliability and maybe not finding the exact dimensions or make of equipment you wanted. If you go the used route make sure you inspect any used tank and look for good seams and construction workmanship as well as know the history of the tank itself. To look for used equipment try local papers, online auctions, trade magazines as well as hobbyist groups such as SEABay.

Other costs you will have to deal with as mentioned before are stocking the tank and monthly operational costs.

Stocking costs - The initial stocking cost will be your live rock and any fine substrate you plan on using. The amount of live rock you use will depend on your goals and the type of rock used but 1.5-2 lbs/gallon is not unusual. Assuming $4/lb for live rock (depending on the type of rock this may be higher) this makes for nearly $2000.00 for rock alone on our example tank, figure another $200-300.00 for sand and salt, more if your planning on using live sand. One way to reduce this set-up cost is to use less live rock by using built up platforms to place the live rock on so it looks like there is really more than there really is. You can use eggcrate along with PVC pipe and fittings to construct your "rock" platforms. Alternately you can combine base rock (i.e., non-live rock) with fewer pieces of live rock. Given time, the base rock will become live as organisms move from the original live rock to the new surfaces. The main concern with using base rock is making sure it is safe for use in marine tanks, ideally you wish to use dead coral (make sure it is not bleached or has at least been neutralized) or other naturally occurring marine materials.

Beyond the rock and sand is the specimens themselves, as this will happen over a longer time period you can spread these costs out but for an estimate of eventual costs (for a reef tank again) you can use about $30/36 in2 of surface area in the tank (costs can vary considerably according type and actual number of specimens). For our example 240 gallon tank this would come out to about $2000.00, adding fish and misc. inverts might increase this an additional $500.00 or more, again depending on number and rarity of specimens added. Use of smaller specimen fragments either purchased or traded for can significantly reduce your critter costs but require more patience to wait for them to grow out.

Operating costs - Figure for the example 240 gallon reef tank, that the monthly electrical bill will be on the order of $100-250 depending on where you live, larger tanks will again scale up accordingly. Ways of significantly reducing these operating costs are normally centered around either finding some way of reducing the artificial lighting requirement and/or controlling temperature regulation costs.

The primary way of reducing the lighting costs is to be able to have some portion of the lighting to be natural sunlight. This can be partially achieved through use of skylights or light tubes of various types. In the extreme case you can place the tank in a temperature controlled green house but the increased costs of controlling the temperature in this case may completely wash out any cost reductions in operating the reduced artificial lighting system.

Temperature control has been mentioned before and with it the concerns of reducing the tank heating during hot days and heat loss during cold nights. If the tank is to be built into a wall or alternately only one face is required for viewing then insulating the other sides of the tank can help reduce these temperature swings and thus the cost of controlling them (i.e., chillers and heaters duty cycles are reduced). Similar insulation treatment should be considered for the sump to reduce temperature variations there as well. Lastly, remember for cooling, it is much cheaper to encourage water evaporation through use of fans blowing over tank and/or sump tops than having to rely on chillers to do all the work themselves.

A properly set-up and well managed BIG marine aquarium is a magnificent sight to behold. But to achieve this goal you need to know what you are getting yourself into and this means planning ahead of time what your needs and requirements will be. It’s hoped that the discussion here has helped you understand some of the issues with both planning and setting up a large marine aquarium as well as the financial implications of doing so. It is a lot of work and will not be cheap but the results are well worth the effort to those of you willing to take the challenge.