Methylene Blue, Pure Powder Form

Fish Disease Treatment: 24 grams makes 1 pint (16 oz). 6 grams makes 4 oz. Use 1 drop per gallon.

Treatment: 2-3 mg per liter.  A simple way to dose is to add 1 drop at a time, max of 10 drops per gallon, until the water is a light to medium blue.  It is best to not overdose as it will have a negative affect.  Always treat in a separate quarantine tank as the chemical dye will kill off the bacteria required to sustain a healthy biological cycle and process waste.

Toxic to live plants.

Can be used with invertebrates.

Silicone seals and decor may become stained and remain blue.  I once had a glass tank where the glass became tinted from this product.

Avoid skin contact.  Methylene Blue is an irritant and not easily removed. Avoid getting on clothing as it will be a permanent stain.

Treatment of Eggs: When pulling the eggs from the parents place the breeding slate or cone in a hatching container.  Add Methylene Blue one drop at a time.  The water should be a light to medium blue and the eggs should remain visible.  Approximately 40-45 hours after spawning the eggs should be removed from this chemical dye as it is known to burn the gills and is suspected of causing the swim bladder to not properly inflate, greatly affecting the fry’s ability to swim and remain suspended in the water column.  All traces of Methylene Blue should be removed prior to the eggs hatching, which will occur around 48 hours after spawning if kept at 80F.

Dip Treatment: Kills external parasites such as flukes, ich, oodinium and some protozoa.  In a quarantine tank place fish to be treated.  1/2 tablespoon per gallon of water.  Color will be a very dark blue.  Leave fish in this dip for no more than 10-15 seconds to avoid gill damage.

Nitrite or Cyanide Poisoning Treatment: When fish have been exposed to cyanide or high levels of nitrite their ability to take in enough oxygen is greatly depleted.  Treating these fish with Methylene Blue can help to raise the oxygen levels as it increases the oxygen carrying hemoglobin in the blood.

Preventative or Low Dose Treatment:  1 teaspoon per 2 gallons water should produce a light to medium blue color.  Add fish to this solution for a maximum of 1 hour with saltwater species or 10 minutes for freshwater species.

Natural Habitat for Discus

Discus are found in floodplain lakes and flooded forests of the lowland Amazon River basin and some of its tributaries, including the Rio Negro.  These areas experience extreme changes in water level due to seasonal flooding.  Discus tend to congregate near fallen trees, known as “galhadas”, along the shore.  They prefer quiet water, and are rarely found in areas where there is strong current or wave action.

Discus Water Requirements

Discus prefer warm, soft, acidic water.  pH should be between 6.0 and 7.0, with hardness between 1° and 4° dKH (18 to 70 ppm).  Temperature should be kept between 82° and 89° F. Water conditions for both wild and hybrid discus are the same. While captive bred discus can be kept in dechlorinated tap water  reverse osmosis or deionized water supplemented will ensure the the best conditions. Discus require pristine water quality, and depending on the filtration system being used, a weekly or bi-weekly water change of 10% to 25% is highly recommended. Don’t forget to treat tap water with conditioner before refilling your aquarium!  

Housing Requirements for Discus

Discus grow to be quite large, and full sized discus will require an aquarium of 50 gallons or larger when they reach adult size.  Tall aquariums are best, to accommodate their body shape.  Current should be gentle, and décor if used at all should include large broadleaf plants and driftwood that is arranged vertically to simulate downed branches and trees.  A few floating plants can also be added to provide shaded areas and cover. Substrate should be fine to medium grade and smooth surfaced, as discus like to forage along the bottom for food.

Discus Behavior/Compatibility

Discus are generally calm, peaceful fish, but as cichlids they can be aggressive toward one another, especially when attempting to pair off and spawn.  Shy or submissive fish should be removed if they are unable to compete. Most serious hobbyists do not mix their discus with too many other species. However, suitable aquarium mates include cardinal tetras, neons, emperor and rummy nose tetras, as well as clown loaches and dwarf cichlids such as rams and Apistogramma species. All of these fish tolerate the high temperatures and low pH/hardness required by discus.  

What do Discus Eat?

In nature discus eat a considerable amount of plant material and detritus, but also forage along the bottom looking for worms and small crustaceans.  They are omnivores and will thrive on freeze dried black worms, beefheart, frozen blood worms, and a variety of pellet and flake food. Frozen and live foods may be fed as treats or to help induce spawning.  For best results, rotate their diet daily and feed only what they can consume in 2 to 3 minutes, once or twice a day.

Discus Breeding Level – Difficult

Captive bred discus will pair up and spawn relatively easily, but young, inexperienced parents may eat their eggs the first few times, particularly if other fish are present.  After hatching the young feed on heavy body mucus secreted by the parents for a few days until they begin to free-swim.  Parents will transfer the young back and forth several times a day.