Algae and Green Water
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Anywhere you find a healthy body of water, you'll find algae. Found only in a cycled tank or pond, over a period of time, you may see that your tank or pond water is turning yellow or green. If the tank is newly cycled, we call this an algae bloom. Once the environment becomes established, and the friendly bug colonies are producing enough nitrates; plant food; algae will form. Mother Nature, creating a perfect balance.
Since algae feeds on nitrates; it assists in keeping levels low, and creating
a safer environment for the fish; making our job a little easier.
If the surface of your cycled tank or pond is quiet, the water may turn a deeper green; known as green water algae, or you may see free floating algae at your pond's surface known as string algae, or you may notice a build up of algae on the sides of your tank or pond, known as substrate algae.
Some forms of algae unintentionally suffocate or eliminate oxygen from water; some, by covering the water surface area, where oxygen is absorbed into the water. This algae is called string or blanket algae.
Some species of algae reduce oxygen levels in the water just because they take up space; rapidly reproducing; pushing oxygen out of the water, such as green water algae. These forms produce dangerous conditions for goldfish and beneficial bacteria alike. The only safe algae for goldfish is 'substrate' algae.
If you have green water; increase your surface action and within weeks the green water algae will turn to substrate algae.
How to grow algae
Goldfish love to nibble on algae and it is a very healthy snack for them, providing a rich source of nutrients and roughage. Goldfish have been known to live off nothing but algae.
Requiring only low levels of lighting, a plant light or natural sunlight combined with the presence of nitrates must be present to encourage algae growth. In a cycled tank, nitrates are the last of the toxins to convert. Algae feed on nitrates, creating a balanced ecosystem. Only cycled tanks and ponds have algae.
How to get rid of green water or algae
To eliminate green water, increase the oxygen levels in your tank or pond by increasing the surface action in your tank or pond; get it churning. The oxygen will take up the available space, pushing the algae aside. In no time at all the algae will begin attaching to any substrate available in the environment. If you don't like the look of it, and want to eliminate substrate algae from your system, reduce the amount of light your tank receives or temporarily black out the tank; but remember that goldfish need a minimum of 6 to 8 hours a day of natural light for good health; this is only recommended for short time periods.
As you're blocking out light; eliminate nitrates; the plant's source of food. This can be done by increasing the amount of water changes in your routine. Water treatments that eliminate nitrates; actually convert them to a safer form; but algae can still feed from the converted nitrates. Nitrates must be removed by means of fresh water change. Once the algae has been removed keep a close and watchful eye on nitrate levels.
Algae is either green or brown in color. It appears darker brown when submerged beneath water, but at the top of the water line you may notice it's much greener being exposed to fresh air.
- What color is algae?
You may have seen, or just heard folks talking about pink or red algae yellow, blue or even white algae, but
this isn't actually algae; it's a harmful bacteria that has taken on a few
characteristics of algae; fungus, and is found
only in a poor ecosystem whereas green algae is found only in healthy
Algae contains chlorophyll, and requires nitrates; unlike fungus.
If the algae in your tank or pond is any color except for green or brown; eliminate it by performing the salt treatment, but in order to eliminate it permanently, a healthy ecosystem must be created. Increase oxygen levels by increasing surface action. Harmful bacteria cannot tolerate heavily oxygenated water. Once the culprit has been removed, provide natural or proper aquarium lighting up to a maximum of 8 to 12 hours daily.
Some of these rare forms of bacteria require intense lighting for extended periods of time. Cool water temperatures; most forms of bacteria prefer warmer water conditions. Check for phosphates in tap water. Some of these forms thrive in water high in this mineral or chemical form; either one. Goldfish Salt Treatment
Since we know that algae feeds on nitrates, we can assume that having algae in a tank or pond keeps nitrate levels low providing a safer environment for goldfish. Dangerously high nitrate levels oxidize the iron atoms in hemoglobin, reducing oxygen supply to the blood stream and tissue. This condition is called Methemoglobinemia; closely related to the effects of DCS. This condition is typically fatal and may also cause bent positioning in goldfish. Nitrite poisoning causes a similar condition.
Curled or Bent Positioning
Whether you keep your fish in an aquarium or pond, algae is the goldfish keeper's best friend.
A few years ago, I went to visit a friend; she'd just bought 5 tiny goldfish at the five and dime. They were comets; brilliant splashes of color painted the fish calico. Being an expert on the subject, I offered my advice on keeping goldfish; and even gave her a spare pump; for she had no filtration, no pumps, no mechanics whatsoever.
The plastic tub the fish called home; was a forty gallon,
plastic tank; cut lengthwise. One side of the cut was the tank; offering less
than twenty gallons of water and the other side became a hinged top, she
explained; a deterrent for cats and bad weather. However, I never saw the tank
with its lid closed. It sat on her small front porch; just at the end of its
cover; getting between two to three hours of sun (depending on the season) each
Benefits of Chlorophyll
Each time I went to visit; I became more and more frustrated with her for not adding the small pond pump. When I asked what she was feeding; she confessed she'd quit feeding them since they had expressed no interest. "You've got to feed them something," I told her politely, but firmly, explaining the need for surface action and oxygenating the water. I did my best to convince her to perform weekly water changes, but her response was; "but the water looks clean," she defended.
After a while I gave up on her, and waited for the bad news, but it never came. The goldfish grew bigger and bigger; their coloration deepened. They thrived feeding off the lush growth of substrate algae lining the tank.
Is dumb luck the key to my friend's accidental success, or is Mother Nature to be credited. She was fortunate that the tank cycled before the goldfish were poisoned by toxins; she was lucky with her choice of location because the sun played a very important role in the survival of her goldfish. Algae formed; grew fast and furiously feeding off nitrates; offering the goldfish a safe and natural environment. It provided bountiful nourishment with high roughage and last, but not least; an endless nesting ground for beneficial bacteria.
The algae substrate formation was encouraged by the sun; consuming carbon dioxide and producing oxygen in the water; the tank needed no surface action; the fish needed no additional food. They had everything they needed inside these twenty gallons.
I do not recommend anyone try this on their own goldfish; but I do highly recommend substrate algae for goldfish ponds and tanks.