Frequent Aquarium Questions

• Are aquarium laser systems harmful to fish and plant life?
  
  
• Is it ok to have all blue lights in my saltwater tank, I do not have any plants?
  
  
• I have a 5-month old, 100-gal fish-only saltwater aquarium set up outdoors and receives a fair amount of indirect sunlight. Is artificial light still needed for the well-being of the fish?
  
  
• I have a 20 Gallon Aquarium with 2 Archers, 2 small Plecos and 1 Bircher. (All are 3" and under) The tank has been set up and running for about 4 Mos. It has good filtration and I do regular water changes. However, the plants I try to keep in the tank keep turning yellow, then transparent and then they die. I think there is something wrong with my water. Should I lower the pH?
  
  
• I have a 1915 (7250 litres) gallon coral reef aquarium whose water level is approximately 36 (90 cm) inches in depth. I am using 2 x 400W metal halides fitted 15 (36 cm) inches above the water level, and 4 x 30W aquastar flourescent lights but do not feel the lighting is adequate. How much and what type of lighting should I use?
  
  
• I bought a 55 gallon aquarium in a Department super store. The aquarium came with two individual hoods, each one with an 18" fluorescent lightning tube. The tubes are identify as natural daylight F15/T18. What does this description means? Can I use this type of lightning to keep some corals in my tank ?
  
  
• In a reef tank what would be the ideal time frame to operate an acintic blue and 10,000k light? They are on separate timers.
  
  
• Do different colors of light affect the growth of Goldfish?
  
  
• My question deals with the right amount of light and the correct quantity of fish. I’ve reviewed extensively the answers and articles you provide about these issues on your wonderful website, however I find myself at odds. I’ve come across at least two conflicting answers provided for each of the issues above!? Allow me to elaborate. Regarding light, one reply noted that 3-5 watts of power is adequate for every gallon of water. However, in another reply 7-10 watts was advised for every gallon. In the matter of the fish, I find myself even more baffled. I read in one reply that the general rule for the number of fish to be kept in a tank is “one-inch-per-gallon.” However, it was advised to a fellow enthusiast that a 75 gallon tank will support 18 inches of fish. Now that doesn’t exactly follow the one-inch rule now does it? Perhaps these answers conflict due to the varying nature of each tank, so allow me to depict my future aquarium if you will. It is a 29 gallon tank that
  
  
• How long do I leave the light on in my aquarium?
  
  

• Are aquarium laser systems harmful to fish and plant life?
  
  They should not hurt plants, but we aren't sure about fish. Read the warnings on any laser pointer for example that say "Do not shine directly in eyes or permanent eye damage may result". That may be a clue.
  
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• Is it ok to have all blue lights in my saltwater tank, I do not have any plants?
  
  You should not use ONLY colored lamps to light the tank. Fish need a wide spectrum of light that simulates natural sunlight for a natural photoperiod and in order to manufacture certain vitamins. Invertebrates also need a broad spectrum of light.
  
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• I have a 5-month old, 100-gal fish-only saltwater aquarium set up outdoors and receives a fair amount of indirect sunlight. Is artificial light still needed for the well-being of the fish?
  
  Unless the tank actually receives some direct sun light, I would recommend using aquarium lights for at least four hours a day.
  
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• I have a 20 Gallon Aquarium with 2 Archers, 2 small Plecos and 1 Bircher. (All are 3" and under) The tank has been set up and running for about 4 Mos. It has good filtration and I do regular water changes. However, the plants I try to keep in the tank keep turning yellow, then transparent and then they die. I think there is something wrong with my water. Should I lower the pH?
  
  You need more light. This is not a problem with water chemistry. When plants turn transparent or turn yellow, it means the chloroplasts in the plant are dying. Chloroplasts are cells in the plant that contain chlorophyll which manufacture food for the plant by converting energy from light into carbohydrates. Chlorophyll is green. If the plant does not get enough light, the chloroplasts die, and the absence of chlorophyll makes the plant leaves transparent or yellow. You need to add additional fluorescent lighting to the tank. Simply extending the light period will not be enough. We should also caution you that many species of Plecostomus will eat plants.
  
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• I have a 1915 (7250 litres) gallon coral reef aquarium whose water level is approximately 36 (90 cm) inches in depth. I am using 2 x 400W metal halides fitted 15 (36 cm) inches above the water level, and 4 x 30W aquastar flourescent lights but do not feel the lighting is adequate. How much and what type of lighting should I use?
  
  Forgive us, but as most of our visitors are from the United States, and the U.S. is behind the rest of the world in that we still use the SAE rather than the Metric system, I have converted the maesurements in your question to SAE.
  
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• I bought a 55 gallon aquarium in a Department super store. The aquarium came with two individual hoods, each one with an 18" fluorescent lightning tube. The tubes are identify as natural daylight F15/T18. What does this description means? Can I use this type of lightning to keep some corals in my tank ?
  
  The F15/T18 means the lamp is 15 watts and is one 1-1/8" in diameter. All standard aquarium lamps are usually natural daylight lamps that duplicate some of the properties of sunlight. However, to grow live corals in a marine reef tank, you'll need bewteen 150 watts and 250 watts of appropriate spectrum lighting. The best bets are either a power compact lighting system or a metal halide system, botn of which usually come with the correct lamps. You will need to get rid of the full hood and get glass canopy tops for your tank to use those lighting systems.
  
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• In a reef tank what would be the ideal time frame to operate an acintic blue and 10,000k light? They are on separate timers.
  
  Run the Actinic lamps for ten to twelve hours a day and the 10,000K lamps for eight to ten hours a day. That way you can achieve a dusk and dawn effect.
  
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• Do different colors of light affect the growth of Goldfish?
  
  No, but all fish require a full spectrum lamp and colored lamps should not be used in aquaria.
  
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• My question deals with the right amount of light and the correct quantity of fish. I’ve reviewed extensively the answers and articles you provide about these issues on your wonderful website, however I find myself at odds. I’ve come across at least two conflicting answers provided for each of the issues above!? Allow me to elaborate. Regarding light, one reply noted that 3-5 watts of power is adequate for every gallon of water. However, in another reply 7-10 watts was advised for every gallon. In the matter of the fish, I find myself even more baffled. I read in one reply that the general rule for the number of fish to be kept in a tank is “one-inch-per-gallon.” However, it was advised to a fellow enthusiast that a 75 gallon tank will support 18 inches of fish. Now that doesn’t exactly follow the one-inch rule now does it? Perhaps these answers conflict due to the varying nature of each tank, so allow me to depict my future aquarium if you will. It is a 29 gallon tank that
  
  This is actually TWO questions, but we'll let that slide for the moment. For the first one, while 3-5 Watts per gallon is an excellent starting point, many aquariums can be successfully (and beautifully) run with additional light, up to and including the maximum of 10 you mentioned before (or more!), as long as the water temperature remains stable. Furthermore, additional light is needed for taller aquariums and hexagonal or oddly shaped ones. This does not even get into the matter of the type and quality of the light in question. Lastly (about light), some organisms require subdued lighting, while others require much greater amounts of light--you must investigate the needs of the animals (and plants) you intend to keep. Now, for stocking guidelines: For freshwater, I suggest the inch of fish per gallon rule with several caveats owing to different fishes' levels of aggression (or lack therof). For saltwater, the rule is modified to about an inch of fish for every ten gallons, with many more exceptions than adherents to that rule. For marine aquaria, aggression is often a much more pertinent consideration, and you could have as few as one fish in a 55 gallon aquarium, or as many as 40 fish in a 55 gallon reef aquarium. The difference in this small example is perhaps that the single fish is huge and the reef fish are usually very small. I won't elaborate on the myriad of marine environments one can create these days.
  
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• How long do I leave the light on in my aquarium?
  
  For fish-only aquariums, you should have the lights on eight to ten hours a day. If you have a freshwater live-planted or a marine reef tank, the lights should be on ten to twelve hours a day and you should be using stronger lighting. Search our other FAQ for more details.
  
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