That’s why you should always switch on the room lights before you turn on your tank LEDs. So, you can see why turning on your aquarium light in a completely dark room can alarm your fish and could even hurt your fishy friends’ eyes. In fish, the process takes around 30 to 60 minutes. Brightnessįish are unable to dilate and contract their iris as quickly as you and I can. However, fish vision is not as sharp as that of humans and can appear blurred and contrasted.Īlthough that might seem like a disadvantage, fish can actually make out objects pretty clearly through a high-contrast image. Predatory fish can typically focus on one single object, whereas other species that are foragers rather than hunters cannot. For example, fish that live in deep water environments, such as the ocean, cannot see the color red. However, it’s thought that the shades and hues the fish can see are a bit different from yours. Most aquarium fish can see colors in much the same way that you can. So, both your fish and your plants need light each day to thrive. However, aquatic plants need between 8 and 10 hours of overhead light every day to enable them to photosynthesize and grow. Plants provide shelter and hiding places for shy fish and vulnerable fry.Plants oxygenate the water through photosynthesis.Plants help to keep the water clean and healthy for your fish by absorbing nitrates for use as nutrients.Plants add aesthetic interest and beauty to your tank.Underwater plants make a wonderful addition to any freshwater fish tank: Light deprivation can cause your fish to lose their bright colors, and a lack of light can also make spawning much less likely. If the fish live in an environment of perpetual daylight, their body clock won’t know when it’s time to eat or rest, leading to confusion and stress.Ĭonversely, too little light can also cause problems for your fish.Too much LED light can cause your fish to stop eating.That can stress the fish, compromising the creatures’ immune system and leaving your pets vulnerable to attack by bacteria and parasites. Too much light can overstimulate the fish, causing them to be active for longer.If your fish and other livestock are exposed to too much LED light, a few problems could arise. In addition, many fish appreciate the inclusion of dense planting or hiding places in their habitat so that they can get away from the lights when they want to. You’ll notice that nocturnal fish species will hide in caves or underneath pieces of wood during the day, only emerging when your tank lights go out at night. Of course, not having eyelids means that fish can’t physically shut out the light. But fish live in water, so that problem doesn’t arise. The purpose of eyelids in mammals is to prevent the eyeball from drying out and to keep it clear of foreign bodies, such as dust. Remember that most species of fish don’t have eyelids. If your fish tank doesn’t have any lighting, the fish will quickly become stressed as their natural biorhythms are disrupted. When the sun rises, the fish know that it’s time to feed, and when the sun sets again, the fish rest.Ĭonversely, nocturnal fish come out to hunt and feed under cover of darkness, staying hidden during daylight hours. However, diurnal fish species need to know when it’s day and night. In fact, lots of fish species come from a natural habitat where the light is relatively dim and shaded by overhanging trees.

Most fish species do not need bright lights in their tank to thrive. How so? After all, the degree of light in a fish’s natural environment is diffused by vegetation or the water’s depth, whereas in a fish tank, the light tends to be much brighter to enable you to see your fish. In fact, your fish need lights in their tank to remain healthy and thriving. No! LED lights won’t harm your fish or hurt their eyes. Read this article on LED lights to find out more about the pros and cons of using LED lights in your fish tank! Is LED Light Harmful to Your Fish? So do LED lights hurt fish eyes? Well, the good news is that LED lights don’t harm your fish! LEDs are the cheapest lights to run, and they’re also some of the brightest. In fact, many tanks come with LED lighting rigs included as part of the tank hood. These days, you can buy lighting units that offer lots of different styles and colors of illumination, including LEDs. The right choice of lighting can transform the most modest fish tank into something quite spectacular!

Fish tank aquarium black light