Malawi Bloat – the dreaded disease

“Malawi Bloat” may be the name of this feared cichlid disease, but the truth is that it affects all cichlids from Africa, whether they are from Lake Malawi, Lake Victoria and especially from Lake Tanganyika.

Malawi Bloat is mostly a death sentence for the fish it affects. The cure success is lower than with all other diseases. The key is therefore to avoid it altogether. But for this, we need to understand all we can about this disease.


  • The first symptom is a loss of appetite. This is why regular observation of your cichlid tank is so important. If you do not take immediate action at this point, other disease characteristics follow and you will most likely lose your fish. These secondary characteristics include abnormal swelling of the abdomen (hence the name “bloat”),  an increased respiratory rate, a tendency to reclusiveness, white streaky feces, and either sitting on the bottom of the tank, or lingering at the surface. Red marks around your fish’s anus, or skin ulcerations might also be apparent.
  • If you noticed nothing before and only now see these secondary symptoms, it will probably much too late to rescue your fish, because by this time extensive damage has already occurred to the fish’s liver, kidneys, and/or swim bladder. Death typically results within 24-72 hours after the onset of these secondary symptoms, although some fish may hang on for more than a week in this condition. It is not typical for more than one fish to be ill with this condition at a time, but other infected tank mates usually tend to die off at intervals of a week or so.
  • Malawi Bloat is primarily characterized by a distended stomach. Without an immediate decrease in feeding, the disease then advances to a point where the stomach acquires a cylindrical appearance. In extreme cases, the entire fish appears swollen, and the scales will stand away from the body, giving the fish the appearance of a pine-cone. Indeed, when this affects goldfish, it is often referred to as “Pine-cone disease.” This body swelling is more properly called ‘ascites’.
  • Bloat is indicated by the stomach being uniformly distended; if the swelling is more of a lump than a swelling, it is probably a tumor, which is almost always incurable. Postmortem examinations of fish which die from Bloat show the livers covered with a yellow, fatty substance. Secondary bacterial infections usually occur, but chances are that this is simply the result of the stress caused by liver failure and possibly by kidney failure as well.


The good news is that three of the main causes for “Malawi Bloat” have been identified:

FIRST:  The addition of large amounts of salt (NaCl) with the intent of simulating a more natural habitat. True, the rift lakes of Africa are alkaline and have very hard water with a pH of 8.0-8.9, and a General Hardness between 200-400 ppm, but common salt will not alkalinize your tank.

What makes water “hard” is a combination of dissolved calcium and magnesium. If you have soft water and need to raise the pH/hardness of your water, I suggest you use SeaChem’s Cichlid Salt, and/or the use of crushed coral as a substrate. Rocks, like limestone, are also helpful in raising the pH of aquarium water, but because minerals don’t stay suspended in water for long, it’s important to do frequent water changes. We discourage you from using any wood in the tank, as it will only serve to lower the pH of your water, even if its effects are minimal.

SECOND: Long term exposure to poor water conditions. Poor water conditions stem from infrequent water changes, a lack of sufficient aeration (for the denitrifying bacteria), and especially from overfeeding. All three of these factors leads to elevated nitrate levels in the water. Fish are very good at fighting off disease on their own, but when exposed to poor water conditions over a long period of time, they become stressed and their immune systems no longer  function at optimal level (just as with us!). What actually causes the diseased condition seems to be a parasite that is always there but only becomes invasive when the fish is stressed. There is still some disagreement as to whether it is actually a protozoan or bacterium that causes the intestinal tract infection.

However, it cannot be emphasised enough: African cichlids are very sensitive to water quality. If you do not keep up a regular weekly water change routine, and keep on ensuring that your water conditions are impeccable, you are playing with fire!

THIRD: Improper diet and Overfeeding. In fact, overfeeding is probably the primary cause of Malawi Bloat. The old adage, “feed your fish what they can eat in five minutes” does not apply to the majority of cichlid species. You should only feed what they will eat in a minute or two. If they are not eating voraciously, cease feeding your cichlids for at least two days.  (It may surprise you, but it may be actually be better for your cichlids to feed only every other day!)

Herbivorous Cichlids have long intestinal tracts, and therefore, it is quite common for them to have intestinal problems. Just to give you an idea of how long they really are, Cichlids’ intestines are FOUR TIMES their body length!

The decomposition of improperly digested, or improperly excreted foods can irritate the intestinal wall, and stress the fish, giving the invasive parasite a foothold. This often comes about when a primarily herbivorous, algae scraping cichlid (like Tropheus spp.) is fed high protein foods such as bloodworms, or pellet and flake foods containing large quantities of fish meal. In light of this information, and experience, it is important to avoid certain foods, and to go light on others.



This is a thin, red worm that lives in mud of rivers, and is usually collected from polluted rivers. By feeding Tubifex to your fish, you are exposing them to the diseases these worms may be carrying.

Red blood worms

Some people have fed bloodworms lightly, without any known incidents; however, those in the know  caution against them.

Beef Heart

Fish are unable to utilize fat from warm-blooded animals for energy use. As a result, these fats build up in the liver, and over time will result in the degeneration of their livers. For this reason, meat from any warm-blooded animal, and especially beef heart, is bad for your fish. Also understand that warm blooded animals carry an entirely different set of invisible parasites, fungi and bacteria that fish have NO tolerance against. That’s why most fish foods are made with Fish Meal, not beef, chicken, or pork! It’s not natural. It doesn’t happen in nature (with the exception of Pirahanas) and it should not happen in captivity either. Fish eat other fish, algae and the occasional worm or crustacean!

Any food meant for American Cichlids

These foods are very dangerous for African Cichlids because the two classes of fish have such drastically different dietary needs.

Brine shrimp

See below.


Brine shrimp

The issue of feeding cichlids with brine shrimp remains one of the most contentious. One School holds that one of the worst foods you can feed Cichlids (because of their long intestines) is brine shrimp. In their opinion, even for Cichlid fry, Brine Shrimp is a big NO-NO. Why are Brine Shrimp so bad? Brine Shrimp are tiny crustaceans and therefore have slightly hard exoskeletons. Because of this texture their hard parts get caught in intestinal walls, while their small size allows them to stay caught in there, causing a blockage. Think of it as the same way Velcro works.

The second school happily feed their cichlids brine shrimps without any problems. So what is the truth here?

I think I found a partial answer recently whilst reading up about Malawi Bloat. Apparently there is a very successful Tropheus breeder in Michigan that feeds all of his Tropheus frozen brine shrimp daily and never has a bloat problem. However, because of the amount of fish he ships, he changes water daily. Also, his tanks are thickly covered with a mat of algae.

We look at a special combination here: an algal mat that provides natural food, and extremely clean water. In view of the fact that water condition plays such a big role in preventing Bloat (as well as other diseases), and that in the case of the breeder natural algae is available for the fish to pick on all day long, we can safely assume that if we grow algae  on the rocks and the back wall in our tanks and keep our water meticulously clean, we could indeed feed brine shrimp — if, for caution’s sake,  only as an occasional treat!

The choice is yours!

Just one word of warning: If your fish are not used to frequent water changes, don’t go for the 50% all at once option, as the shock of new water could be too much. Rather step up your water changes gradually.

Pelleted food

Pellets tend to swell a great deal after they have been put in water; therefore, you must soak them before feeding them to your fish — particularly so because cichlids are greedy feeders. You don’t want the pellets to swell inside your fish’s abdomen, because un-soaked pellets can seriously distend, irritate, or even cause the digestive tract of the fish to explode. Pellets have been one of the biggest culprits in most of the deaths due to “Malawi Bloat.”

Frozen food

Any food that is high in protein, such as krill, brine shrimp, daphnia, plankton, bloodworms, and micro-worms should be used very sparingly. They should not be used at all for herbivorous cichlids. Use these foods only as occasional supplemental treats to the cichlids’ main diet of Spirulina flake food.  Feed frozen foods only once it has completely defrosted and been broken up. If you toss in half-defrosted food, an aggressive cichlid will more than likely snatch the whole cube — and then wake up the next day with a bad case of the Bloat. Defrost frozen food in a cup of hot water and use a stick to break it up. Feed frozen foods only once or twice a week, and then no more than your cichlids can consume in 30 seconds. Because cichlids are such avaricious eaters, they can consume a great deal of food in 30 seconds or less.


Flake food

You should never feed your cichlids more than they can consume in two minutes, not five! It is preferable to feed cichlids several times a day, so that they don’t gorge themselves on large amounts of food at any one time. If this is possible for you, reduce the time it takes your fish to consume the flakes to 30 seconds. This is the more natural way, because in the wild cichlids nibble on algae, plankton, or Artemia (a.k.a. brine shrimp) throughout the day. This spread-out method of feeding, as well as the correct food mix helps to prevent all digestive problems. Remember, cichlids have long intestinal tracts. Flake food is ideal, because it is quickly digested, and does not clog your cichlids’ intestines.


Of all Flake foods, Spirulina should feature right at the top of the list in very large letters,  because it is very nutritious and high in healthy protein. Peas are good too. Both are natural laxatives and will keep things moving along smoothly in the long cichlid intestines, avoiding the potential for Bloat.

Most other flake foods, even the vegetarian flake foods,  contain some high protein meat, including Krill, Brine Shrimp and worms. The difference is that when these foods are combined with veggies in a flake or pellet food, they are not “whole”. The ingredients are crushed and pulverized into powder and in some cases even sterilized, thus lessening the potential for foreign hitchikers, or the dreaded ‘velcro effect’ you may encounter with live brine shrimp.

The best way to tell how appropriate a food is for herbivores, is to make sure the minimum amount of protein in the food you buy is under 40%. Anything higher than 42% seems to cause Bloat problems and 46% to 50% is way too rich. HBH, Hikari, Omega One, Nutrifin, Dianichi and New Life Spectrum all have excellent veggie blends that have all kinds of other good veggies like Kelp, Algae, Carrots and Alfalfa for your Herbivores. Your Cichlids will get all the protein they need in veggie food, as well as the other ESSENTIAL veggies that will help that protein move along those intestines just fine.

The safest treat foods for mbuna (non hap) cichlids are those that are predominantly vegetable based, such as peas, zucchini, and romaine lettuce. If you freeze these vegetables and then thaw them, they will soften up and can be consumed quite readily.

While I agree that when we consider the question of Bloat and the necessity to prevent it, we must differentiate between piscivores, along with the Malawian cichlids that eat insects and molluscs, and those that munch Aufwuchs (the algal mats covering the rocks in the lake) for a living, I have come to the following conclusion: You can actually feed all your African Cichlids, including the carnivores, with nothing but Spirulina Algae based and Veggie Blend foods. Your fish will thrive, and be more disease resistant — and you will never have a problem with Bloat. The one proviso is that your water must be clean!



Once you notice that your fish has lost an appetite for food (make sure you are not dealing with a female just holding fry in her buccal cavity), you should remove it from the tank and begin treatment immediately. I have found two treatment ‘recipes’ that differ slightly, so I post both below.

Method 1

  • DO NOT FEED ANYTHING during this process.
  • Start this procedure as soon as the fish shows symptoms (spitting familiar food, hiding during feeding, etc.)
  • Medication required: Clout (Aquarium Products) or any medication containing Trichlorphon as the main ingredient. If you cannot find something with this drug, then a cure with Metronidazol is recommended (ie: Jungle’s Internal Parasite Guard or Jungle Parasite Clear Tablets.) Metronidazol is also known under one of it’s brand names Flagyl. Clout (Triclorphon) is the most widely used cure for bloat, though.
  • Day 1: Move fish to quarantine tank and treat with Clout at full strength (1 tablet / 40 litres–remove carbon from filter). The water should be heated to about 28°C.
  • Day 2: No water change. Treat again with Clout at half strength.
  • Day 3: Do nothing
  • Day 4: Do an 80% water change and treat with Clout at full strength
  • Day 5: Do nothing
  • Day 6: Return fish to main tank only after symptoms have subsided and the fish has been healthy (eating, swimming, breathing normally) for a week.

RESIST the urge to try feeding the fish until after the treatment is over and do not cut the treatment short regardless of whether the fish looks better or not. If at any time during the treatment your fish seems to be experiencing stress as a result of the medication then do an immediate 75% water change.

Method 2

  • Treatment should be immediate.
  • Ideally the affected fish should be isolated in a separate small tank without gravel.
  •  Use any kind of biological filter, such as a sponge filter, or an airstone.
  •  The water should be heated to about 28°C.
  •  Don’t use carbon in the filter because it will lock up the metronidazole, the medicine of choice described below.
  • The water should be hard and alkaline.
  •  Add about 2.2 teaspoons of salt per 4 litres, preferably Instant Ocean or similar, but any non-iodized sodium chloride is fine.
  • Use 2 tabs (or capsules, or 1/8 teaspoon scoops) of Metronidazole per 40 litres of water the first  day.
  •  The following day change about 90% of the water (maintain the same salinity of 2.2 teaspoons per gallon, maintain the temperature at about 28°C.)
  •  Now use 1 tab (or capsule, or 1/8 teaspoon scoop) of Metronidazole per 40 litres of water.
  • Repeat the water changes and the re-treating with metronidazole and salt for at least 7 days.

If the “Malawi Bloat” problem is diagnosed and treated early enough, the treatment described above works 50% of the time.

One additional treatment

The only other treatment that has a positive effect on bloat is Epsom Salts. Not only does this product  act as a laxative for the affected fish, it also acts to draw excess moisture out of the fish, which also helps the condition especially if it is caused by Gas Bubble Disease. Why am I mentioning this? The problem is that Bloat can be imitated by one other condition — Gas Bubble Disease. GBD causes a “pine cone” or raised scales appearance and happens most often in during the winter months, because we tend to add hot water to our water change water in order to keep the tank temperature regulated. But hot water, when it comes from a water heater has gas bubbles in it. The only way to get rid of these gas bubbles is though gas exchange — meaning a heavy aeration of the water. A simple aquarium air pump in the warm water about 30 min to 1 hour before changing your cichlids’ water will get rid of the gas bubbles. The reason it happens is the more heat used to keep the water hot in the hot water tank the more gases build up in the water, because your water heater works harder in the winter to keep the water hot.  What happens to your fish if you don’t get rid of the gas bubbles in the water? The same thing that happens to a diver when they don’t decompress properly, they get “the bends”. The fish version of “the bends” looks exactly like Malawi Bloat. The gas bubbles in the water get trapped under the fish’s scales and cause the scales to appear raised (pine coned). These same gases also get into the fish’s bloodstream. So if you suspect that your fish have got GBD rather than Malawi Bloat then the first course of treatment is Epsom Salts and if that doesn’t improve the condition of the fish after a day or two, then use Clout.

Using the various methods outlined in this guide to Malawi Bloat should  dramatically increase your fish’s chances of never ever getting the disease, or for surviving Malawi Bloat. Even if you should have the misfortune to lose fish to the bloat, don’t feel too bad. It is a a tough disease to beat, even for the most experienced of fish keepers, which is why the mention of Bloat always makes most experienced fish keepers cringe,  because they know it’s a 50/50 chance the fish will live, even with treatment.

To conclude, lets look at a summary of things we can do to prevent Malawi Bloat:

  •  Feed only green spirulina foods to all herbivorous cichlids.
  •  Make sure all food is fresh … don’t buy more than a 12 week supply.
  •  Keep food covered, clean, and dry.
  •  Go lightly on protein foods
  •  Always make sure the tank water is hard, alkaline, slightly salted, well-filtered & oxygenated.
  •  Frequently perform substantial partial water changes
  • When picking fish from a dealer’s tank make sure that all the inhabitants are healthy, active and feeding well.