White Slime in a Saltwater Aquarium

Air fresheners can contaminate aquarium water, causing white slime.
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The ecosystem of an aquarium is delicately balanced. Native bacteria populate the water and their presence controls the growth and abundance of other flora, such as algae. A healthy aquarium should have crystal clear water, but sometimes things can go wrong. If you’ve got a white slime growing in your aquarium, it is most probable that the balance of chemicals in the water has become disrupted.

White Slime Causes

The most probable cause of white slime in a saltwater aquarium, according to Lance Ichinotsubo, author of The Marine Fish Health & Feeding Handbook, is the presence of the airborne bacteria Alcaligenes faecalis. This bacteria causes a thick, white slime to grow in the water, hanging in a jelly-like state in the water. As well as being unsightly, this slime poses a risk to the balance of the aquarium and to the health of its inhabitants.

Risks to the Aquarium Ecosystem

Any slime growing in an aquarium is a sign that the delicate ecosystem is out of kilter, but in the case of this thick, white slime, it is a potential hazard as well as an indicator of poor water health. This slime, due to the rate at which it grows and its jelly-like consistency, can choke native fauna, such as coral. This causes the water oxygen levels to drop dramatically, causing the fish to die from suffocation.

How Did it Get There?

The bacteria Alcaligenes faecalis has no natural reason to be in a saltwater aquarium. Two cases of white slime investigated by Lance Ichinostubo found alcohol and plug-in room deodorizers to be the most likely culprits. The alcohol didn’t get into the aquarium through drunken negligence, however. In this particular case, the white slime was affecting the aquarium in a dentist office. The dentist was using alcohol to sterilize his instruments, resulting in airborne alcohol particles finding their way into the water. In the second case, the plug-in room deodorizer was pumping out an alcoholic mist into the atmosphere.

Ridding Your Aquarium of White Slime

The first and most important step in tackling the white slime is to remove any items that generate airborne mist, such as the notorious room deodorizers and alcohol steamers. Avoid further contaminating the air in the room in which you keep the aquarium by spritzing perfume. The second step is to use water treatment additives to break down the slime already in the water. Routine water maintenance products require you to add small amounts regularly, rather than a single large amount. This process can take weeks, so patience is essential.

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