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Video:Why Do Fresh Water Aquariums Become Green?

with Dan Thornton

It can be frustrating if your fresh water aquarium starts to turn green, but this is a fairly common problem. Here is a video explaining the causes of fresh water aquariums turning green.See Transcript

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Transcript:Why Do Fresh Water Aquariums Become Green?

Hi, I am Dan Thornton, owner of Reef Encounters in Erie, Colorado. I am here for About.com to talk about why fresh water aquariums sometimes turn green.

Fresh Water Aquariums Turn Green From Algae

Fresh water aquariums turn green due to algae growth. There are several types of algae; one of them is in the water and most algae grows on the glass. When you have the type of algae that is in the water, the water itself will turn green. It's not necessarily harmful to the fish, but it looks bad, so it is a good idea to find out what is causing it and fix the problem. Things that cause any algae growth are the amount of light, the amount of nutrients going into the tank, and the amount of filtration, or fish.

Causes of Algae Growth in Fresh Water Aquariums

The easiest thing to control is the amount of light. If you notice that you are getting direct sunlight through a window, you can move the aquarium, or put up some blinds, or window tinting, something to limit the amount of light. Direct sunlight is probably the biggest cause of algae problems. Sometimes algae growth can come from an overabundance of nutrients, specifically from nitrates and phosphates. They usually come from the food you are feeding the fish. If you are feeding too much food, through the nitrogen cycle the food is eventually converted to nitrates. It's taken out of the tank when you do a water change, or algae and plants will also use nitrates. So if there is too much nitrate in the tank, you are going to get more algae growth. How much you feed the fish is a very easy thing to control. Try feeding every other day for awhile and see if that fixes the problem.

Phosphates Fueling Algae Growth

Phosphates can also come from the breakdown of leftover food and a lot of times will actually come from your municipal water. If you are having a bad problem, you might want to try testing your tap water, to see if you are adding phosphates when you replace the water. To deal with phosphates, there are different phosphate sponges and chemical filtration means to control your phosphates.

Maintain Filters to Keep Aquarium From Turning Green

It's important to make sure that you are maintaining your filters by changing out the cartridges when they get clogged or rinsing sponges. You need to make sure you have adequate filtration on your aquarium. If you have too many fish, and your filter is not able to break down the waste fast enough, you will end up with ammonia and nitrite which are excellent sources of nitrogenfor green algae, even more so than nitrates.

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