Due to vacations, other recreational activities and lack of time, our tanks may no longer look their best. When this happens we generally notice that a lot has happened to the tank that needs improving. Algae may be a little thicker, the water may not be as clear and the corals may not be as healthy and vigorous as they were when we were spending significant time on the tank in the cooler months. In the worst-case scenario, fish may be missing, corals dead or dying and the algae so thick that the live rock cannot be seen.
Where to start?
Fortunately, even when a tank has been badly mismanaged, it can usually be brought back up to speed with only a moderate amount of effort. When a tank has been set up properly it is usually not necessary to tear the tank completely apart as was often the case when undergravel filters were used. The key to restoring a tank is to determine what produced the problems and then how to gradually rectify them. The reason that patience is required is that in many instances, where water conditions have deteriorated over time, the tank’s inhabitants have gotten accustomed to these conditions. If the water conditions are then rapidly changed, even if it optimizes the conditions of the water, the drastic rapid change can shock or kill the animals. Therefore, all of the changes and improvements should not be done at once, but rather they should be done gradually over several weeks to give the animal’s adequate time to acclimate to them.
Testing your water
The first step in getting a tank back to optimum condition is to determine where all of the conditions are. To do this a simple assessment of the tank’s conditions, water parameters and equipment should be assessed and recorded. This may sound complicated, but all it really entails is testing the water, checking all of the equipment and determining how well it is working. The tank should also be closely observed and both its positive and negative attributes should be noted. In terms of testing the values that should be assessed include: temperature, pH, salinity, alkalinity, calcium, ammonia, nitrate and phosphate. Once these are assessed and recorded, the next step is to determine how these compare with the optimum values and if there is a dramatic difference in these values and why. The optimum values will not be discussed in this article as they are readily available in many texts. Some of the values that are of particular interest and some of their causes include high nitrate or ammonia levels. These could be caused by the recent deaths of animals, heavy accumulation of detritus, the introduction of chloramines into the water supply or heavy overfeeding by someone who was fish sitting. High phosphate levels can be the result of some of these same activities as well as from an improperly functioning reverse osmosis membrane, or a deionization resin that has been used up. High levels of these compounds may then lead to an algae bloom or to high levels of dissolved organics being present in the water that makes it look yellow.
Checking your aquarium equipment
Improperly functioning equipment can also produce less than optimum water conditions as well. Some things that should be looked at include salt spray on the lights, reflectors, covers or glass braces. Any spray can dramatically reduce the amount of light that is transmitted. The age of the metal halide, T5 or Power Compact bulbs should also be noted as well as their output. Replacing used bulbs is often neglected in the summer. The output should also be assessed, as during the summer when it is generally brighter the bulbs may appear to be producing bright light, but if their output has diminished it may be masked by the sunlight entering the room. The bulbs on UV sterilizers should also be assessed at this time and their sleeves cleaned to optimize their usefulness. If the bulbs are more than 12 months old they should be replaced.
The effectiveness of the protein skimmer should also be assessed. This should include noting how long it has been since the venturi, injector or protein skimmer pump has been cleaned. The time since the entire unit has been broken down and cleaned should also be noted. If in either case it has been longer than six months then the skimmer should be cleaned. Other filtering devices should be similarly assessed. The outputs from pumps and powerheads should also be assessed and if their output has fallen they should be taken apart and thoroughly cleaned. If this does not improve their output then they should be replaced. All heaters should be checked to see if they are intact and working. This may seem unnecessary since it is still warm, but since a complete tank assessment is being done this vital piece of equipment should be assessed as well. Making sure that a heater that has not been in use for months is intact is important in that often this item gets banged and broken during the summer, but since it does not come on there is no problem. However when it does come on in the fall or winter, if the glass is cracked or broken the results can be a severe shock or worse. Lastly, the bottom of the tank behind the live rock as well as the sump or refugium should be inspected to determine if excessive detritus has accumulated as well as whether the flow through these areas is still optimal. If detritus is excessive then t should be remove during the water changes and if it is a problem in the tank, increased flow should be utilized to reduce it in the tank.
Planning your attack
Once the conditions and equipment have been assessed, the next step is to plan what needs to be done in order to get the tank back to the desired state and in what time frame. As noted above, changing everything quickly and dramatically is not the best option as it can have as much of a negative impact as letting things deteriorate. At this point it is also time to determine what fish or corals need to be replaced or what is going to be added. However, these animals should not be added until after the tank is brought back to the proper condition. It is also generally easier to improve things incrementally from a time perspective as well. That is, it is easier to find fifteen minutes to clean the lights or protein skimmer than it is to find five hours to do everything at once.
Removing algae and cleaning the protein skimmer
Once this assessment is done and a plan laid-out, the first thing that usually needs to be done is removing excessive algae and keeping it under control. This is usually the result of detritus build up over the summer due to inadequate water changes having been done. Along with this, the efficiency and productivity of the protein skimmer has often decreased. The remedy for this is twofold: the skimmer should be taken apart and soaked in a dilute acidic solution or a commercially-prepared equipment cleaner. This will optimize air intake though the venturi or injector system, which will maximize bubble production. This will also help to reduce the oily buildup that occurs over time and allow more foam to be produced. After soaking the unit, it should be rinsed thoroughly so that no residual acid gets into the tank. In many cases after a thorough cleaning a skimmer will foam to a much greater extent than it had previously. This is due to the cleaning allowing it to remove waste at a lower threshold and so right after a cleaning the skimmer may overflow. This over foaming may take as long as three days or more to subside after a cleaning so precautions should be taken to prevent the skimmer from overflowing and causing damage.
Perform a big water change
While the skimmer is being cleaned or adjusted, new saltwater should be prepared. The amount prepared should be 25-30% of the tank’s volume. This is a larger water change than is typically recommended, but if the nutrient levels are high, this will actually only reduce their level by 25%. Thus, even after doing four 25% water changes the nutrient levels will still be approximately 30% of what they were initially. This is due to the diluting effect of each water change.
This large of a water change can shock the animals if it is not done properly so care and adequate preparation needs to be done. Newly prepared synthetic seawater is very caustic so it needs to be made up and allowed to “cure” before it can be used. The easiest way to do this is to mix the salt and clean water free of nutrients in an inert container a week before it is needed. A powerhead should be placed in the container to thoroughly mix it and to maximize the air/water interface. A small amount of carbon can also be placed in the container in a bag to further reduce the caustic nature of the salt.
Once the water has been conditioned and its temperature, pH, and salinity match that of the tank, the water change can be performed. If excessive algae growth is one of the problems that has occurred, this is when it should be taken care of. The glass should be cleaned and scraped and any algae on the rocks or substrate should be scrubbed off. Algae scrapers, pads and magnets are great for this task. Unless the algae is totally out of control, this scrubbing can be done in the tank. When this is done, the skimmer may over foam so precautions should be taken. If there is an excessive amount of algae or if the algae is especially difficult to remove from the rocks, it may be necessary to remove the rocks and scrub them outside of the tank. This should be done in a small bucket of tank water with a coarse scrub brush.
Keeping up with water changes
After the first water change, plans should be made to continue weekly or biweekly 25% changes until the nutrient levels reach their desired low levels. As noted above, this will still not bring the levels to zero. If the skimmer has been cleaned, it should help, but it also might be time to use a nutrient removing resin or carbon. By using resins such as GFO and carbon, it should be possible to reduce phosphate and the dissolved organic levels to very low levels. In addition, natural herbivores and detrivores such as snails, hermit crabs, sea cucumbers and sea urchins can be added to keep algae from gaining a foothold and to consume some of the detritus.
Cleaning the lights and glass cover and replace bulbs
Once all of this is done the water should be cleaner with less of a yellow cast and this will improve light transmission. This is also a good time to clean the lights, reflectors and glass of any salt spray and to replace any old metal halide, T5 or Power Compact bulbs. This should
not have been done earlier, as the excess nutrients present would have simply allowed algae to grow quickly. However, once the nutrient levels have been reduced, the lighting can then be increased without adding to this risk.
The fun part: Adding livestock
Once all of these conditions are optimum new corals and fish can be added. Doing all of this may take three to four weeks, but when done properly it will allow any new introductions as well as the old inhabitants to thrive. There is an added benefit to being patient and performing these tasks gradually, and having a marine tank that is successful long-term is the goal of every saltwater enthusiast.