That Fish Blog – Aquarium Advice and Information

“Slime algae” is a common problem with aquarists of all levels but getting rid of it can be tricky. The name “slime algae” is a misnomer and what may looks like a slime in your tank could be a number of different problems or, more commonly, a symptom of a number of different problems. The key to getting rid of it is to identify and eliminate the cause rather than just treating the symptom.

As with most aquarium problems, diagnosing this problem starts with testing your water quality. Water tests are just like vital signs at a doctor’s office and can point to or eliminate a lot of different problems in an aquarium. In addition to the four core water tests – Ammonia,Nitrite, Nitrate, and pH – testing the Phosphate level is also important in algae and algae-like issues like this. We’ll go into more detail later with how each parameter may be causing your problem and how they can be used to solve it.

Next, take a look at the “slime” itself…we’ll use these different appearances to help narrow down which you might be seeing in your tank. What color is the algae – red, green, black, brown, white? What is the texture like – thick and mat-like, a thin coating, wispy, cloudy? Do you notice it growing anywhere particular on the tank – only on the substrate or a certain ornament, in a circulation deadspot, only towards the top? Can it be easily brushed away? Are there bubbles forming beneath it?

Now to the different “slimes”…

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Thick and mat-like, usually dark red (especially in saltwater) or dark green (especially in freshwater). Bubbles form underneath the mats and it is easy to brush off of surfaces.

This is the most common “slime algae” that aquarists encounter but it isn’t actually an algae at all even though it may behave like one. This is Cyanobacteria (often simply called “cyano”). Cyanobacteria are bacteria that manufacture their own food and live in colonies — large enough for you to see them! It’s these colonies that cause trouble for aquarists. They are not necessarily blue-green but can be black, green, blue green, and the familiar dark red sheets covering many surfaces in an aquarium.

The first thing aquarists who find an unwanted colony of cyanobacteria in their aquarium want to know is how to get rid of it. Well, this is where it gets tricky. To eradicate the problem, the particular trigger for the cyano bloom must be identified and treated. Not every bloom is in response to the same trigger and while throwing a chemical at the problem will perhaps clear it up temporarily, it will come back, and it will be worse. Cyano has a few common causes:

• High Nitrates (NO₃-)/Dissolved Organic Carbon (DOC): These two parameters go hand-in-hand and are often interchangeable for an aquarist’s purposes. Nitrate and DOC is a food source of the bacterial side of the bacteria-algae. Sources include: fish slime, algae, bacteria, digested/uneaten food, metabolic waste, live food, some aquarium additives etc.
  • Key Appearance: The cyano with this cause will grow fairly indiscriminately anywhere in the tank where it gets light. This is usually the thickest mats of cyano.
  • Solution: This is best done by frequent water changes, good water movement (power heads and closed system circulation ) and (this is important!) a good protein skimmer (for saltwater tanks only). An undersized or ineffective protein skimmer, high waste loads, or a combination thereof will increase the dissolved carbon level. As a rule of thumb for skimmers; buy one that is rated for at least twice the size of your tank. It may take some adjusting but a properly functioning skimmer can remove ½ cup of thick organic scum from a tank a day. Also, watch what you feed. Feed once a day. If you wish to feed twice, simply split the amount in half – don’t feed twice as much food. If you feed grocery store bought seafood or are making your own foods, rinse all foods thoroughly as seafood sold for human consumption is treated with phosphates and preservatives to keep it fresher longer. (It’s true!) Avoid flake foods, these dissolve too fast – pellets and crisps are much better and more palatable.

• High Phosphates (PO₄^3-): This level is similar to the Nitrates above and may come from some of the same sources. It is used as a preservative in some foods as mentioned, but is usually the result of the water source. If you are using tap water, be sure to test the water before adding it to your tank, especially if it is well water or if you are in an area with a lot of agriculture and run-off. You can also check with your municipality if you use a municipal or “city” water source since Phosphate may not be removed in all areas.
  • Key Appearance: Similar to above.
  • Solution: Frequent water changes with Phosphate-free water. If your water source already has high Phosphate levels before it even makes it to your tank, consider installing an RO/DI (Reverse Osmosis/Deionization) Unit . This filtering system removes all impurities (including Phosphate, Nitrate, and DOC). If you already have an RO/DI Unit, make sure all the membranes are installed correctly and changed regularly. If you aren’t able to install your own unit, many stores like ours sell RO/DI water by the gallon. Filter medias are also available to help remove Phosphates faster than water changes alone.

• Lighting:The food source for the algal side of the bacteria-algae is light. This is becoming less common as LED lighting is replacing older fluorescent aquarium lighting but if you are still using fluorescent bulbs, check on the age of your bulbs. Light bulb spectra (the “color” of the light) shift as they age, resulting more favorable conditions for photosynthesis to take place more vigorously. Older bulbs become more yellow in color and the “good” plants and algae can’t use this spectrum as well as the “bad” algae and cyano can.
  • Key Appearance: If lighting is the cause, you are most likely to see the cyano forming in the most brightly-lit areas of the tank with the most direct light. Since light wave penetrate differently through the water column, you may see a gradient in the cyano growth from top to bottom.
  • Solution: Replace old bulbs. If your fluorescent bulbs are older than 6-8 months, it is time to replace them. Even if they still “look” bright, the color will have started degrading. If you are able to, consider switching to an LED fixture. In addition to being much more energy efficient, they don’t age and lose their spectrum in the same way fluorescent bulbs will.

• Poor Circulation: In this case, you may see cyano in only certain areas of the tank like corners or areas sheltered by rockwork. In these areas, the circulation is blocked or can’t reach sufficiently and any waste can build up before it can be removed by the filter. This provides a captive food source for the cyano.
  • Solution: Rearrange your tank or install powerheads or pumps to increase the circulation. Consider upgrading your filter as well if it isn’t powerful enough for the tank size.

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Thin and wispy sheets, usually on the substrate and especially in freshwater tanks. Usually green, brown, or blue-green

Trick question! This is also Cyano. This appearance is more common in freshwater tanks and in higher-flow environments where the Cyano can’t settle into thick mats. The same causes and solutions above still apply.

It should also be mentioned that there are chemicals to “treat” Cyano. Cyano is a gram negative (thin cell membrane) bacteria, much like most bacteria in the aquatic environment. A dose of Erythromycin will knock out the colony of slime quite quickly and this is the active ingredient in most Cyano chemicals on the market. However, since the nitrifying bacteria you need in your tank are gram negative as well, they will be affected also, either being killed or severely damaged. This treatment is more advisable in freshwater aquaria, but only with careful attention paid to water quality while treating. Like all antibiotics, if dosed frequently the cyano will develop a resistance. This should be a short-term fix only, and the problem leading to the cyano bloom in the first place still has to be addressed to eliminate it for good.

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Thin light brown coating on exposed surfaces, especially in new aquariums (less than 4-6 weeks) or in tanks that have recently been “restarted” with a large water change (over 40-50%), medication, or other event

A few weeks after the tank has started cycling (after live rock, fish or a bacteria culture has been added), you may see a thin brown film covering the surfaces and sides of the tank. This film scrapes or wipes off easily and cutting back lighting doesn’t seem to affect it. No snails, hermit crabs or fish feed on it, but critters moving across the substrate or glass tend to stir it up enough so it “goes away.” So, what is going on at this point?

The “algae” you see is not a type of plant with cells like traditional green algae that most people think of. It is actually made up of diatoms, a type of phytoplankton whose cell walls are primarily made up of the mineral silicate. It blooms towards the end of the cycling process in a tank because of the imbalance of nutrients in the system but will usually die off on its own once the water chemistry in the tank stabilizes. This is what we commonly refer to as “New Tank Syndrome” (NTS).

• Solution: Just wait! As tricky as it may be, the best tool to combat NTS is patience. Once the cycle progresses and the tank becomes established, this diatom bloom will exhaust itself and fade away on its own. You can clean the sides of the tank and stir up the substrate to break up the algae, but avoid the temptation to do water changes or add any algacides at this point….this will only cause the cycle to take even longer to finish and the NTS will keep coming back. Most tanks take about 4-8 weeks to cycle, depending on the bioload and size of the tank.
• For more information, see our article Explaining the Nitrogen Cycle.

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White, mold-like coating often isolated to a single ornament (especially natural ornaments like driftwood) in a freshwater tank

This is usually a sign of fungus or decomposition. If the “slime” is translucent in appearance, it is more likely to be a fungal growth. This is common on ornaments that may have been left outside and exposed to airborne spores, or on pieces washed with some detergents. If possible, remove the piece from the aquarium and scrub it thoroughly in a bucket of tank water or under warm running water. Spider Wood especially is notorious for becoming moldy when first added to a tank but will usually dissipate on its own in time.

If the “slime” is more opaque in color and easily brushes away, something is decomposing. If this is a natural material like a once-dried-out starfish or another animal, dispose of it…it will only continue to decompose and harm the water quality. If it is a harder object like a piece of wood, you can try cleaning it like described above but if it continues to soften or fall apart, it likely just isn’t a safe type of wood and should be replaced as well.

These are just a few of the most common “slime”-related issues we encounter often but are far from everything you may experience. We have come across some really unusual circumstances that have turned out to be related to something as seemingly unconnected as an oil-diffuser air freshener in an outlet near the tank. Feel free to let us know if you need help troubleshooting with your own tank!

Originally published September 9, 2008. Updated May 13, 2020.

Frank Indiviglio here with an introduction to Echinoderms.

Sea stars, or starfishes, are perhaps the most familiar of the Echinoderms (a phylum containing over 7,000 marine species), and many adapt well to aquarium life.  Most people are quite surprised to realize that they are active, interesting predators that routinely exhibit a wide variety of behaviors in the aquarium.  Many are also useful scavengers, but all are predatory in nature and, depending upon the species, will consume mollusks, coral polyps and other sedentary invertebrates.

Red-knobbed Sea Star, Protoreaster lincki
When picturing a sea star, many people think of the simple reddish-orange animal so often seen as a dried curio in beachfront shops.  However, many are fantastic in appearance and coloration.  The Red-knobbed Sea Star, with brick-red dorsal spines set off against a dazzling white background, is a case in point.

Native to the Indo-Pacific region, this perennial aquarium favorite reaches a length of 12 inches and is capable of consuming quite large mollusks.  It is best fed by placing a piece of clam, scallop or mussel directly below the body, although it is quite active and capable of finding food on its own.

Although sea stars are quite adept at sensing and locating food, they respond more slowly than do most fish.  Therefore, they will usually remain hungry in a mixed-species tank unless care is taken to see that food is placed directly below each animal.

Brittle Stars
Brittle stars bring the word “bizarre” to mind instantly, even to those well acquainted with the sea’s curiosities.  They react very quickly to the scent of food, and their long, slender arms thrash wildly about as they begin to explore.  It is quite a sight to see a tank housing several of these normally sessile creatures suddenly come to life – the many sinuous arms seem to take on a life of their own, yet the animals glide unerringly toward the source of the odor that aroused them.

Brittle stars are harmless to most other creatures and are extremely valuable scavengers.  Perpetually hungry, their thin arms can get into the tiniest of crevices between coral heads and other places where bits of uneaten food might otherwise go unnoticed.

Sea Urchins
These slow-moving, spiny invertebrates are often encountered in tide pools, and are worldwide in distribution.  The spines of all are effective weapons, and many secrete venoms that are as yet not well-studied.  Hot-water baths seem to assist in alleviating the sting caused by most species, but handle all with extreme care.

With over 800 species identified to date, urchin enthusiasts have much to celebrate.  Many unusual species are commercially available, including the Long-spined Sea Urchin, Diadem antillarum and the Pencil Urchin, Heterocentrotus mammillatus. Both feed primarily upon algae, but will also consume bits of fish and shrimp.  The Long-spined Urchin is armed with extremely sharp spines, much to the chagrin of bathers in tropical waters.  The Pencil Urchin is well named – its spines, less numerous than those of other urchins, are very thick and blunt-ended.

Wave your hand above a captive or wild sea urchin and you will likely be surprised at how quickly the seemingly inert beast responds.  A shadow or object passing overhead is viewed by an urchin as a predator, and all the spines are oriented to face the threat.  Although parrot fish, sea otters and wolf fish are adept at clipping off urchin spines or turning the animals over to expose the soft underbody, the defense is, in general, foolproof.

Despite their slow-moving ways, sea urchins are quite active and seem bent on getting into every possible nook and cranny in their aquarium.  Be sure to check that they do not wedge themselves too tightly into small corners, or tumble backwards into coral and become stuck.

I’ll cover individual species in depth in future articles.  Until then, please write in with your questions and comments.  Thanks, Frank.

You can read more about sea urchins, sea stars and their relatives at:
http://tolweb.org/tree?group=Echinodermata&contgroup=Deuterostomia

Welcome back Patty Little Back with profiles on two more types of freshwater shrimp you may find interesting and consider adding to a peaceful community tank. These are species that we commonly carry in the retail store.

Cherry Shrimp
Cherry Shrimp, Neocaridina heteropoda, are named for their deep red, speckled coloration. They originated from Northeast Asia and this is not their color in the wild; they have been selectively bred to enhance the reds. Their natural coloration is reddish brown to brown to help them blend to their environment. Cherry Shrimp are common, colorful, cheap, and hardy. They are an ideal beginner shrimp as they may survive in conditions that many shrimp will not tolerate.
Cherry Shrimp thrive in a wide array of conditions. Ph from 6.0-8.0, soft or hard, temps from 72-84 will be tolerated with ease. They will eat about anything from flake and pellet to fresh and frozen offerings like spinach, spirulina, bloodworms and a variety of other offerings, but though healthy specimens will attack food with vigor, they do not need to be offered food every day. Overfeeding can cause health issues and fowl the water.
Cherry Shrimp only grow to be about an inch in length. Males are easily distinguished from females as they are significantly smaller and have less intense coloration. A small colony of 5 or 6 shrimp will give you good odds of having both sexes. These shrimp are known to be quite prolific and will breed regularly and produce fry which can be raised easily under good conditions and as long as no fish are present. Mature females will show a yellow-green “saddle”, which are actually eggs developing in her ovaries. The fertilized eggs are carried by the female under the tail for 2-4 weeks until the young shrimp hatch and disperse. The tiny shrimp babies are identical versions of the parents. Colonies of these shrimp are easy to establish and small species set-ups can be ideal to really get to know these fascinating little guys! Image referenced from Wikipedia Commons, http://upload.wikimedia.org/wikipedia/commons/1/13/Two_red_cherry_shrimp.jpg

Bamboo Shrimp
There are several different types of filter feeding shrimp that are available in the aquarium trade. One of the coolest, I think, is the Bamboo Shrimp, aka Fan Shrimp, Wood Shrimp, Asian Filter Shrimp, Mountain Shrimp, and Singapore Shrimp. This species, Atyopsis moluccensis, is quite attractive and bold in a predator free tank, a worthwhile addition though they can be a little pricey. They grow to 2.5-4 inches in length and at that size they can easily become a centerpiece member of your aquarium community. They are safe for docile tankmates despite their large size, as they are filter feeders.
Bamboo Shrimp occur in a varying range of colors, but are typically some shade of red, tan, or brown. A cream colored to yellow stripe runs down the center of the shrimp’s back, and thinner stripes line the flanks. The most appealing physical characteristic of these shrimp are the fan-like filtering appendages they use to collect food. The fine filaments open to collect tiny bits of food (as opposed to claws like most shrimp) which are swiped through the shrimp’s jaws. Feeding requires that the shrimp is able to sit in an area of current, so some keepers suggest that wood or some other furniture is placed in an area of moderate flow so the shrimp has a good place to perch and feed. Periodic feedings of liquid invert foods may be appreciated, but in great moderation so water quality does not decline.
Bamboo shrimp can live for several years under good conditions. They prefer Ph between 6.5 and 7.5, temps between 72 and 82F. These shrimp need specific conditions to breed and reproduction with this species is not something that will occur in a freshwater aquarium as the larvae need varying degrees of salinity as they mature before returning to freshwater as mature specimens. This species is captivating and if given the right conditions can be a real conversation piece for aquarists. A large planted tank with plenty of flow will be prime real estate.
I hope to blog on some other less common freshwater shrimp in the next installment of this series, tune in again!
Patty

Please welcome back Brandon Moyer with another entry on invasive species

The next species I would like to present to you in my exploration of invasive species is one that is notorious among biologists across the country. Though it is quite beautiful in bloom, it is known as a super invasive plant species that disrupts habitats and displaces many native species of fish as well as insects, birds, and other small mammals.

The species is Lythrum salicaria, and it may be something you see every day without even knowing it.  It is known by over ten common names including spiked loosestrife and purple lythrum worldwide, but is best known by the name Purple Loosestrife in the United States. Purple Loosestrife was first introduced into North America through several different vectors; as an ornamental plant for ponds and gardens, as an herb used in cooking and medicine, and through ship ballast water. The origin of Purple Loosestrife is unknown, although its current range is vast. It is very hardy, has spread across Asia and Europe, only limited by the extreme cold of the upper northern hemisphere.

Purple Loosestrife spreads in two ways. One adult plant (4+ years of age) can produce over two million seeds in a single season. These seeds tend to float which aids in dispersal. Their rhizomes, commonly known as runners, can grow up to a foot a season. New plants can spring from these rhizomes, which compounds the number of seeds produced each season.

In several biology and ecology courses I had taken at Millersville University, L. salicaria was a popular example of an introduced species that has taken a strong foothold in a new environment. The dense clusters of roots and rhizomes choke out the roots of other plants around the loosestrife, increasing the area in which it can spread and smothering native plants. Their leaves decompose in the fall when the weather begins to cool and detritivore activity decreases, leading to nutrification of infested waterways. Its thick undergrowth deprives native animals like turtles of areas to bask, but is not dense enough to protect other animals from predation.

Today you can see purple loosestrife almost anywhere you see water in the eastern United States including bogs and drainage areas around warehouses and malls. It can be found in every state except for Florida, Hawaii, and Alaska. Conventional methods of eradicating the invasive, including herbicides and burning, are ineffective. One interesting method of control, considered biological control, is introducing other non-native species that prey on the invasive species. In the case of Purple Loosestrife, leaf beetles, root boring weevils, and flower and seed eating weevils have all been introduced to help stop the spread of the weed.
In any case, control is necessary to protect the complex ecosystems of the wetlands that Purple Loosestrife dominates.  You can help by first learning to identify loosestrife, then using methods to control the spread of this invasive species if you find it on your property by digging, pulling, spot spraying or cutting the plants while they are in bloom and before they seed, usually June-Early August.  Remove the plants and cuttings in plastic bags so they degrade, or incinerate the remains of the plants in a contained area.  It is not recommended that they be composted.  Also, avoid certain cultivars of garden loosestrife and their seed, though they may not be invasive varieties, many may be able to cross pollinate with the invasive species.

For more information on Loosestrife visit the following sites:
http://www.invasive.org/eastern/biocontrol/11PurpleLoosestrife.html
http://www.npwrc.usgs.gov/resource/plants/loosstrf/index.htm
http://dnr.wi.gov/invasiveS/fact/loose2.htm
http://www.seagrant.umn.edu/ais/purpleloosestrife_info

Image referenced from Wikipedia http://en.wikipedia.org/wiki/Image:Purple_loosestrife2.jpg, first posted by Megger and used under the GNU Free Documentation License

Thanks Brandon,

Until Next Time,

Dave

 

Please welcome back our “Cichlid Guy” Jose with an article on his experiences with Copadichromis species.

In Lake Malawi, there is a group of zooplankton feeding cichlids known to the natives as “Utaka”. They are the most important and most successful group in the lake. As where most cichlids are bottom dwellers, they have developed into an open water species. Utaka have developed several breeding techniques. Some breed in the rocky habitat and some construct sand bowers in the intermediate habitat, while others breed on the open sand. A fourth strategy is employed by Copadichromis chrysonotus. It is the only known Utaka that spawns in the open water.  In the hobby, young chrysonotus have been confused with young Copadichromis azureus. I have had the pleasure of working with both species, and they are different in size, color, mouth structure and breeding behavior. While the azureus bred under a cave (where he would lure the female with figure eight motions), the chrysonotus bred six inches above the rocks. As much as I enjoyed working with this fish, I have always wanted to breed a species that utilized bowers. The species I came across is Copadichromis eucinostomus. It is found in Lake Malawi, and was previously known as Haplochromis eucinostomus and Nyassachromis eucinostomus. It is found throughout the lake where it feeds on plankton, and its habitat consists of sandy areas in shallow water where males construct “sand castle nests”.

Spawning takes place in the early morning hours. After the eggs have hatched, mouth brooding females congregate into nursery schools and release their fry simultaneously in very shallow water.

After acquiring a wild pair from work, I put them into one of my 75 gallon aquariums. The tank was decorated with caves and a fine Aragamax sand substrate. The water conditions were as follows: Ph 8.8, a hardness of 200 ppm, and a temperature of 82 degrees. Their diet consisted of different flake foods supplemented by occasional feedings of frozen brine and mysis shrimp.

After about one month, the male started piling sand into a mound in a corner of the tank. His color then began to intensify. He went from silver with a light blue face to a light blue with yellow dorsal and caudal fins. From the lower jaw to the anal fin he was black. He then started courting the female to his nest, where she deposited at least two dozen eggs in the normal mouth brooder fashion. At about 27 days I noticed some fry hiding in the rocks. I then removed the rocks in order to catch the fry. I captured 17 fry less than 1/4” in length. The fry then went into a breeder net that was hung in the same tank. They were fed crushed flake and baby brine soaked in Selcon. They ate very well and never turned down food. After three weeks, I transferred them into a 10 gallon tank for growth. This species is generally peaceful at 4.5”. Their max length is 6”, although in the aquarium they can probably get larger. It is definitely worth keeping along with Aulonocara and certain Malawi haps. They are not common along the East coast, but you might be able to find them through forums or specialized clubs dealing with cichlids if we are not able to get them for you. Copadichromis are great looking fish with interesting breeding behaviors. I would recommend if you keep African cichlids to give this family a try, you won’t regret it.

Thanks Jose, as always we look forward to future tales of your experiences.