Reef Aquarium Basics

  • salinity/specific gravity
  • lighting
  • calcium
  • alkalinity
  • phosphate
Salinity/Specific Gravity

Stable temperature of our reef aquariums' water is crucial to maintaining an environment that our fish, corals and invertebrates will grow and thrive in.  Water temperatures over a typical coral reef are generally high, between 75°F and 85°F and rarely dip below 65°F or rise above 90°F.  When they do, it can cause severe fish die offs and coral bleaching.   Therefore, we should try to maintain the temperature in our aquariums somewhere in that general range with 78°F to 82°F being the ideal.  For this reason, an accurate thermometer and heater is mandatory for all aquariums.  Be it a reef or fish only with live rock aquarium, you must have a thermometer and heater to know what the tanks water temperature is and to maintain the water temperature consistent.  Some reef tanks with higher output lighting may need to have a chiller (water cooling system) to help cool the water to an appropriate level.  Most tanks will not need a chiller if cooling fans are installed in the canopy to vent the heat from the lights.  Water temperature should not fluctuate more than 1 to 2 degrees throughout the day.

pH is a measurement of the concentration of hydrogen ions in a solution.  A scale of 1 through 14 is used to quantify this measurement with 1 through 6 being acidic, 7 being neutral and 8 through 14 being basic.  In a reef aquarium pH is a simple test that helps us determine  the water quality of our aquariums.  Typical reef and FOWLR aquariums have pH values anywhere from 7.9 to 8.6 with 8.2 to 8.3 being ideal.  

 Biological Filtration based on Live Rock

Biological filtration is the process of bacteria mineralizing and oxidizing organic compounds produced in our aquariums from fish waste, leftover fish food, coral waste and other metabolites.  There are two basic types of bacteria that grow inside of live rock and sand.  One type is aerobic bacteria (use oxygen) and the other is anaerobic bacteria (do not use oxygen).  The oxygen using bacteria basically take ammonium which is extremely toxic to fish and corals, and convert it to nitrite, which is toxic as well, then convert the nitrite to nitrate which is not harmful to most fish but is harmful to corals and can contribute to algae growth.  This process is commonly know as the nitrification.  With live rock and live sand the process of nitrification is taken one step further.  Nitrate is converted by anaerobic bacteria from nitrate to nitrogen gas that escapes from the tank at the water surface and also through protein skimmers.  This process is known as denitrification.  Without the help of these beneficial bacterias we would not be able to keep the incredible reef aquariums we keep today.   Below are the most commonly used methods for biological filtration of our tanks.
Lee Chin Eng Method

The Lee Chin Eng method was the first natural approach to keeping marine organisms and was developed by Lee Chin Eng of Indonesia in the 1960's.   The method uses live rock, live sand, natural sunlight and an air bubbler for water movement.  Lee Chin Eng used no trace elements or supplemental lighting in his aquaria. 
The reason why he did not use trace elements or calcium addition is because he was doing complete water changes every week on his tanks.  He was able to keep a large amount of soft and hard corals with this approach and he had some beautiful reef displays that ran quite well.  This approach still works today but it does take more work due to the frequent water changes and with todays more modern powerheads and pumps their is no need for the air bubbler for water circulation. 
Berlin Method

The Berlin method for reef keeping originated in Germany, hence the name Berlin.  It involves the use of live rock (at least one third of the tank's volume), live sand, strong intense lighting, protein skimming, strong water flow and the addition of kalkwasser mixed with all make up water for evaporation and trace elements.  Live rock  and live sand provide all the biological filtration for this approach and protein skimming helps to remove organic compounds before they can be broken down by biological processes.  Kalkwasswer is used to provide calcium to all of the organisms that use it to build their skeletons and shells.  Kalkwasser also provides additional benefits because it helps maintain pH and alkalinity, makes the protein skimmer work better and precipitates phosphates. Phosphate is harmful to all organisms that use calcium like hard corals, snails and clams as well phosphate can cause and accelerate the growth of nuisance algae like hair algae.  The Berlin method by far is the most widely used approach for reef and FOWLR aquariums and is the method we use for all our coral holding systems.  This is the method we recommend at Amazing Aquarium Design.
Jaubert Method

The Jaubert method was developed by Dr. Jean M. Jaubert of the Monaco Aquarium.  This method is based on the use of live sand, strong light, live rock and strong turbulent water movement.  This method works by using a deep sand bed (at least 4") placed on top of a false bottom sort of like an undergravel filter except there is no water being pumped through the sand.  The sand is divided into two layers about 2" thick and separated by a screen.  Below the sand is an open area or plenum that is kept sand free.  In theory this approach is supposed to maintain tanks at zero nitrates and also does not need any extra addition of calcium and trace elements.  After running a tank for years with this approach it has been my experience that this is not the case.  calcium and trace element additions are still necessary.  Also it is my experience that sand being placed directly on the bottom of the tank works better for denitrification purposes and traps less detritus if sand sifting cucumbers are placed in the sand.    
The first and most helpful purchase one can make when setting up a new reef tank or fish only with live rock aquarium is to buy an informative marine aquarium book.  Recommended books are:

  • Marine Fishes by Scott W. Michaels