The easiest measurement to take and the one most often overlooked is temperature. A good temperature range is 76-78 degrees Fahrenheit. The lower temperature will allow more room for error, as most biological processes will occur at a slower rate than they would at a higher temperature. A higher temperature’s advantage is that it may increase the growth rate of the fish and corals by increasing their metabolism. If the temperature is too cold, check that the heater is functioning properly and that it is of adequate wattage for the tank’s size and the ambient room temperature. Being too cold is usually not a problem with most tanks; the lighting systems, pumps and powerheads used generally produce enough heat to adequately keep the tank warm. A more frequently encountered problem is that the tank is running too hot. If this is the case once again the heater should be checked to determine if it is working properly and that the contacts are not sticking. If this is not the problem, then the excess heat is usually due to the lights not being adequately ventilated. All lights generate heat, and if the lights or the tank are not cooled by a fan then this heat will be transferred into the aquarium. If this is the problem then more fans should be used to blow across the lights and the water’s surface. In addition, all of the pumps and powerheads also transfer heat into the aquarium. For this reason it may be necessary to add more fans or switch to air cooled powerheads and pumps, particularly in the summer. In the many cases it may be necessary to purchase a chiller or an air conditioner to cool the tank and the room. These are necessary not only for larger tanks, but just about any tank that is well lighted.
One other aspect that is often problematic in a well-lit tank is algae. This maintenance task is not particularly fun. More than any other problem, it is what drives people from the hobby. Removing algae needs to be done on an almost constant basis, otherwise the algae will gain a foothold and become very problematic. The main cause of algae is excess nitrate and/or phosphate. Once again, a log is useful here in that in early cases and when a tank is relatively new, the tank may only need to have the glass cleaned once a week and all of a sudden when it needs to be cleaned 2 or 3 times a week this may be a sign of a problem. It may be that the fish are being fed too much or it may be that the old lights have been replaced with new ones. When nutrient levels are high and the lighting is increased due to replacement this is often enough to cause an algal bloom. No matter the reason it should still be looked into and the cause determined. A maintenance task that is often overlooked, but that should be done every six months is cleaning of the pumps and powerheads. Over time detritus and scum tend to build up on the intakes and the impellers of these devices over time reducing their efficiency. As a result the flow becomes reduced. Therefore twice a year the powerheads and pumps should be turned off, taken out and thoroughly cleaned. If these units are thoroughly clogged it is a good indication that they need to be cleaned more often. Once the powerheads are cleaned their flow should have increased. Therefore after they are turned back on their effect should be noted, as too high a flow rate initially can have just as deleterious an effect as too little.
Another aspect of maintenance that requires some thought is feeding the fish. This should be an enjoyable task, as a well-acclimated and carefully selected marine fish should eat voraciously. However, there are some factors that need to be taken into account when feeding the fish.
First, most marine fish feed constantly when on the reef. In fact, most of a fish’s energy is expended either searching for food or trying not to become a meal for someone else. For this reason, most fish have relatively small stomachs. As a result, the standard habit of dumping a large quantity of food into the tank once a day in not conducive to the long-term health of the fish. Not only do the fish tend to gorge themselves during this feeding, but also because most hobbyists tend to over feed and some food will remain uneaten. This uneaten food will then add to the amount of waste in the tank.
A much better method of feeding the tank, and unfortunately it is the tank that is being fed in addition to the fish, is to put 3 or 4 small feedings in the tank over the course of the day. The amount of food supplied should all be consumed within 1-2 minutes. Otherwise more waste than is desirable will result.
This may seem like a difficult schedule to maintain, but if planned out it is quite easy. A possible schedule would include a light feeding in the morning, before work. The lights may not be on, but there is usually sufficient ambient light in the room so that many of the fish will be active. Therefore a light feeding will provide nourishment to these fish. The next feeding will be given right after coming home from work. This will be the heaviest feeding, as all of the fish should be active at this time. The next feeding can then be given a couple of hours later in mid-evening. The final feeding is then given at least 1/2 hour before the lights are turned off. This reduces the likelihood that any food will be missed and fall to the bottom where it will decompose.
The fish should never be over fed, either at a single meal or over the long term. Marine fish in the wild are constantly hungry, so the amount of food given should be enough to satisfy the hunger, but not enough to fatten them up. An overfed fish has a protruding stomach that is easy to see. If this occurs occasionally, it will probably not harm the fish. However over the long haul, overfed fish have been found to die prematurely with fatty livers. Conversely, if an inadequate amount of food is being fed, the fish will show it by their shape getting gradually thinner, particularly the area behind their eyes where they store extra fat.
This death due to fatty livers is thought to be the additional consequence of inadequate exercise due to poor water movement. In order to reduce the likelihood of this from occurring, the feeding of overly fatty foods should be kept to a minimum and strong water flow within the tanks should be present. If the fish are to go unfed for a couple of days, they should not be overfed prior to this. Not only does this not cause them to be full for the duration, but right after all of this food leads to an increase in waste production. If the fish have been well fed, then going a few days without food should not harm them as there is often lots of food on the live rock and within the tank itself that they will only go after when they are hungry.
In addition to consideration being taken as to how the fish are fed, care should be taken as to what the fish are fed. In nature most fish eat a varied diet so this should also be the case in the home aquarium. A constant diet of flake food will simply not keep marine fish healthy and vibrant over the long term. A varied diet produces positive consequences in a number of ways. First it helps the fish maintain not only their vitality but also their color. In fact, when properly fed a varied diet some fish may improve in color as they get larger and mature.
Over the last few years a large number of marine food items have come into the market. These include frozen krill, plankton, brine shrimp, silversides, squid as well as blended diets. Most of which are designed for specific types of fish. Also some freshwater items can be used such as bloodworms, glassworms, daphnia, mysis shrimp and mosquito larvae. In addition, items from the fish market such as shrimp, fish filets, and clams or oysters on the half shell can be given as occasional treats.
The delivery of these foods is rather simple. In the case of the solid items, such as plankton or krill, a piece of food of the desired size should be cut from the frozen block. This piece should then be placed in a fine mesh net, like those used for brine shrimp, where it should thaw. It should then be placed under running water. This is done to wash away any of the superfine particles that are present in the ice surrounding the food. These particles are too small for most fish, but by washing them away unnecessary waste is kept out of the tank.
In the case of foods from the fish market, care should be taken to wash these foods thoroughly before adding them to the tank. Also they should only be purchased from a market that turns them over often to ensure their freshness. This is particularly important in the case of shrimp and scallops, which may be chemically treated with a triphosphate containing compound to help them retain their appearance of freshness. The shells of the clams and oysters should be thoroughly scrubbed under fresh water to not only remove any dirt or silt, but also to try and remove any bacteria that may be present on their shells.
The frozen foods need to simply be thawed before they are gently broken up and added to the tank. Care should be taken to not allow them to sit out too long or they will become liquid or begin to spoil as they break down rapidly. If the food reaches this point, it should not be added to the tank.
The foods added to the tank should be of adequate sizes so that they can easily be swallowed by the fish. Even large sized food should be cut or chopped to a size so that even the smallest fish can readily swallow some of the pieces. If fish are housed together of different sizes the size of the food pieces should be varied to match these differing sizes.
Lastly the fish should not be fed every time the tank is passed and they follow along and “look hungry”. This is when they have the owner trained. When this occurs, the fish not only tend to get overfed, but their natural behavior patterns rarely show. For this reason, the fish should be fed at different spots along the tank and on a schedule rather than when they look hungry.
One last maintenance task that should be done daily is to sit back and observe the tank. No other maintenance task is as important as this. Only by regularly observing the tank will an appreciation for how well the tank is doing occur. Frequent observation allows one to get a feel for the tank. That is a “sense” develops as to when its going good and when its not. As a result a problem can be seen to be starting long before it becomes a major catastrophe. It should also be noted that this last task should be pleasurable. If not it probably means that the maintenance tasks are not being performed on schedule and that the tank is not thriving.
Mike Paletta is the author of The New Marine Aquarium and Ultimate Marine Aquariums. He has been in the hobby for over 15 years and has written numerous articles for Aquarium Fish Magazine, Tropical Fish Hobbyist and Aquarium Frontiers.