Summertime Reef-keeping

Summer is almost here!  As spring transitions into summer our thoughts are often filled with wonderful days of warmth and sunshine.  While outdoor activities, vacations, and thoughts of the beach may take up a significant portion of our free time, it is important to remember our aquariums.  There are several potential issues that could always pop up throughout the year but should be particularly guarded against during the summer: overheating, power outages, neglect, increased evaporation, and excessive sunlight. Read more about each of these below.

Sunny D Zoanthids always remind me of summer. (It’s probably the yellow.)

Sunny D Zoanthids always remind me of summer. (It’s probably the yellow.)

Is your aquarium Overheating?

Excessive heat can and will kill coral. Coral has evolved over time to survive in a fairly narrow temperature range so make sure you are prepared to address any problems that might cause temperatures to rise. If you live in an area where outside temperatures skyrocket, this may include having preventative maintenance done on your house air conditioner at the beginning of the season.

During the summer months, most of us - for comfort and energy saving purposes - will set our house thermostat higher than we do in the winter time.  Even a few degrees can have a noticeable impact on aquarium temperature, especially if the aquarium is using hot running lights or pumps, has a tight fitting canopy, or is located in a room that gets lots of sunlight.  Pay a bit of extra attention to the daily temperature swings and notice how your fish and coral are reacting.  In the ocean’s reefs it is normal for there to be temperature differences between summer and winter so some variability is perfectly safe but as temperatures creep higher there is an increased risk for problems to arise.  Personally I don’t like temperatures above 80 degrees Fahrenheit but others may push it a bit more.

Check Room Temperature

Overheating is generally fairly easy to solve but first you will want to identify the sources of heat and either eliminate them or find a way to cool the tank in spite of them.  If your tank is overheating, the first thing to double check is your aquarium heater.  If that is working as intended, take note of is the air temperature in the room.  Cooling a warm room might be as simple as closing the window blinds and reducing direct sunlight entering the room.  You may also want to check and make sure any air vents are open, add a fan, or a window AC unit.  An aquarium will (under normal circumstances) never be cooler than the ambient room temperature so it is important to address this issue before looking to other potential problems.

Use a fan to compensate for hot running equipment

Lights and pumps have historically been a major source of heat.  However, with newer, cooler running LEDs and DC pumps this is much less of a problem these days.  If these are a problem and you don’t want to lower the temperature of the entire room any more, sometimes the easiest solution is to angle a fan across the top of the aquarium (or sump).  In most cases a fan can cool a tank by several degrees at the cost of increasing evaporation.  It is important to note that if your lights are the source of heat, you will want to place your fan on a timer to turn on in conjunction with your lights.  Running the fan at night can result in your tank getting too cool thus turning the heater on… a bit counterproductive!  If you have a tight fitting canopy, opening the lid to let out the heat can also have a huge impact.  While you can always upgrade cheaper items to more efficient lights and pumps, these are often the most expensive part of an aquarium and replacing them is generally not an option for most folks. 

Resorting to a Chiller

Last of the potential solutions would be the addition of an aquarium chiller.  I try to avoid chillers in most cases, but other people love them.  I do feel that they were much more common when metal halide bulbs (which are insanely hot) were common.  A best practice for chillers is to have them away from the tank, even better if you can place them in a separate room.  The worst place is to place them within the aquarium stand.  The reasoning behind this is due to the mechanics of the chiller.  Like an air conditioner or refrigerator, a chiller works by removing heat from the water and then blowing that heat into the surrounding air.  By placing the chiller near your aquarium (especially in a small room) it can easily heat the surrounding air which then in turn heats the aquarium faster.  While a good chiller will still reduce the temperature of your aquarium, it will generally need to work harder (and use more electricity) the closer it is to the tank.

RA Shmurple enjoying 79 degree water while the outside temperatures soar over 90! (Air conditioning is amazing.)

RA Shmurple enjoying 79 degree water while the outside temperatures soar over 90! (Air conditioning is amazing.)

Power Outages

Depending on your geographical location, the risk of power outages may increase significantly in the summer months.  For those farther north, this might be a bigger problem during the winter as blizzards and storms pass through.  Here in Virginia we have a much higher risk of power outages in the summer when we get bad thunderstorms than can knock the power out for hours or days.  Other people might worry about tornadoes, hurricanes, or potentially even brownouts as everyone turns on their AC at once.  Whatever the cause, it is important to think about your risk for power outages and take appropriate precautions.

It is generally accepted that the biggest cause of tank death from power loss is a lack of oxygen.  Everything alive in the reef tank is dependent on oxygen to survive.  Even algae, which releases oxygen in daylight, uses more oxygen than it releases when the lights are off.  Under these circumstances, oxygen is rapidly consumed in the reef environment. As soon as the pumps stop, an imaginary clock starts ticking, and it is imperative to begin introducing oxygen within a short period of time or risk the tank crashing.  Coral can go without light for several days but only a few hours (or less) without water movement/oxygen.

If you live in the south, temperature might also be a concern.  For an emergency option you can always wrap the tank in blankets and float bags of ice in the aquarium.  It is probably not a good idea to actually let the ice melt into your tank.  Not only with this lower your salinity but, while probably harmless, who knows what random chemicals might be in the ice.

Should I get a backup generator for my reef tank?

Generators are the obvious solution to power outages.  These can be simple manual units that you roll out and turn on as needed or full house backup generators that automatically kick on when the power fails.  When making a decision about backup power you want to weigh the well being of your aquarium’s inhabitants with the likelihood that your power will fail.  At our facility we never lose power for more than a few minutes.  Even so, we want to ensure we don’t lose the entire business due to a freak storm so we have a backup generator just in case.  While generators are certainly a choice, they are not the only means to provide reef security in the event of a power outage and other solutions might be a better solution depending on the situation.

What are the alternatives to generators?

While a generator will provide stability for a long period of time, there are other methods to ensure your tank is stable when power fails.  A low cost alternative that works well for shorter periods of time is a simple battery powered air pump.  This works best in smaller tanks but multiple pumps can be employed to help oxygenate larger systems.  There are also battery backups which can be used to keep pumps running.  Ecotech makes a special battery pack for their pumps or you could go DIY and make your own battery backup system.

Zoanthids are hardy corals but don’t want to live in a hot tub.

Zoanthids are hardy corals but don’t want to live in a hot tub.

Increased sunlight

We all have noticed that during the summer months days are longer and we get stronger, more direct light from the sun.  If your aquarium is near a window, pay attention to the effects that sun exposure may have on your tank.  As mentioned before, increased sunlight can cause temperatures to rise but more light may also impact coral coloration and health or it might cause excess algae to grow.  General tank placement recommendation discourage situating aquariums near windows so this may not much of an issue, but it is worth paying attention to.

Increased evaporation

Often the changing of the seasons can impact evaporation.  Summer tends to increase evaporation.  If your tank temperature rises, if you use fans to cool the tank, if the humidity in your house drops due to running the air conditioner you might notice a change in evaporation rate.  Pay attention to the speed of evaporation and fill the tank (or your auto top-off system) as needed.  This is especially important if you go away on vacation; make sure there will be enough water while you are gone. 

Use your brain to avoid aquarium problems this summer. ;)

Use your brain to avoid aquarium problems this summer. ;)

Beware of neglect

Nothing says, “tank crash” like neglecting your aquarium while you hang out at the pool/beach/camping/etc.  After spending years in the industry, I can safely say that most people do not spend nearly as much time paying attention to their tanks during the summer months and this sometimes causes significant problems.  There is nothing inherently wrong with not spending hours watching or adding new things to your reef, but make sure you are still doing all the regular maintenance that your tank requires.  It might even help if you put reminders on your phone/calendar to help jog your memory. If you are going on vacation, plan for someone to watch your tank while you are gone. You will feel peace of mind while you are away, and it just might save your entire tank. When wintertime comes and you rediscover your love of reefing, you will be thankful you did not let your tank go to seed over the summer.


Do you have your own advice that I missed? Feel free to share in the comments below! Happy reefing!