Cichlids

Malawi bloat

SignsSwollen belly, white stringy feces, spitting out food, rapid breathing, hiding motionless among rocks, sudden death within days

PreventionDo not feed animal-based foods to herbivorous African species. Keep pH at 7.8 or above and reduce overcrowding stress

Hole-in-the-head disease

SignsSmall pits or holes on the head or lateral line, white stringy feces, weight loss, darkened body color

PreventionCommon in oscars and angelfish. Water changes to keep nitrate from building up; a balanced diet

Ich (white spot disease)

SignsSalt-grain white spots on body and fins, rubbing against rocks, clamped fins

PreventionQuarantine new fish in a separate tank for 2 weeks. Keep the temperature difference at water changes within 1°C

Aeromonas infection

SignsScales standing out like a pinecone, abdominal fluid, red hemorrhagic spots, bulging eyes, ulcers

PreventionPrevent fight wounds. Leave no uneaten food; siphon debris from the substrate once a week

Indigestion / constipation

SignsDistended belly, no or broken feces, loss of appetite. Common in gluttonous flowerhorns

PreventionFeed only what is eaten within minutes per day. Set one fasting day a week to prevent obesity

Gill disease / parasites

SignsOne gill cover held shut, rapid breathing, swollen dark-red gills, mouthing at the surface

PreventionAlways quarantine and treat new fish. Keep ammonia and nitrite at zero

Bite wounds from fighting

PreventionProvide more hiding places than fish. Do not keep multiple males of the same color or species. Add fish all at once or when changing the layout

First aidIsolate the losing fish with a divider or in a separate container. Give a 0.3–0.5% salt bath in clean water. If white cotton appears, treat for fungus

Eye damage / bulging eye

PreventionAvoid fighting and sharp rocks. Scoop with a container, not a net

First aidIsolate and keep the water clean. One bulging eye suggests trauma; both suggests infection; consult the same day

Jumping out / falling

PreventionAlways use a heavy lid. Do not startle. Keep the water level lower for large species

First aidReturn with wet hands and support in gentle current. If the fins have dried, add a slime-coat protectant at the labeled dose

Mouth / lip injury

PreventionPrevent collisions with the lid or glass. Keep mouthbrooding females from being chased

First aidIsolate and offer small, soft food. If the mouth cannot close or the fish cannot eat, consult within a few days

Nontuberculous mycobacterial infection

RouteThrough cuts on hands that touch tank water or fish

PreventionWear gloves if you have cuts. Wash with soap after tank work

Salmonellosis

RouteHand to mouth after touching tank water, substrate or filter media

PreventionDo not pour tank water down the kitchen sink. Wash hands after tank work

Aeromonas infection

RouteDirty tank water entering a wound

PreventionAvoid tank work when you have a wound. Wash hands and arms after water changes

Bacterial infection from spine punctures

RouteHard dorsal spines puncturing the hand

PreventionDo not handle large fish bare-handed; move them in a container. If stuck, rinse under running water

Food

• Species-appropriate formulated food 1–2 times a day, as much as is eaten in 2–3 minutes
• Spirulina-based food for herbivorous African species; carnivore pellets for oscars
• Give flowerhorns one fasting day a week to prevent obesity

Water

• African species: hard water, pH 7.8–8.6; South American species: pH 6.0–7.0
• 1/3 water change weekly. Dechlorinate and keep the temperature difference within 1°C

Toys & play

• Hand-feeding helps them recognize and bond with you
• Periodically rearrange rocks and layout to reset territories
• Oscars play by nudging a ping-pong ball on the surface

Nest, bed & hideout

• For African species, build rockwork with more gaps and caves than fish
• Tall plants and driftwood for angelfish; wide open bottom for oscars

Bedding & litter

• Coral sand for African species to keep pH high
• Fine sand or gravel with planted aquatic plants for South American species
• Assume the substrate will be dug up and moved; secure equipment

Cage / housing material

Glass aquarium. Heavy lid. Powerful canister or hang-on-top filter

Size & space

60 cm or larger for small African species; 90–120 cm or larger for oscars and flowerhorns

Layout

• Place rockwork directly on the bottom glass and glue it so it cannot collapse
• Install the heater with a guard, away from rocks
• Create territory boundaries with sight-blocking obstacles

Placement notes

• The stand must bear the full weight (about 80 kg for a 60 cm tank)
• Avoid direct sunlight, vibration and entryway temperature swings

Exercise, free-roam & walks

• No walks needed. Provide both open swimming space and hiding places
• Lighting 8–10 hours a day on a timer
• Once a day, check every fish's body, fins, feces and breathing

Temperature & humidity

TemperatureKeep a steady 24–28°C with a heater. Daily variation within 2°C

HumidityA lid prevents evaporation and jumping. Top off what evaporates

Summer & winter

• Summer: oxygen depletion above 30°C. Add a cooling fan and aeration
• Winter: keep a spare heater in case of failure. Insulate during power outages

Nail trimming

No nail trimming. Instead, basic care is weekly substrate cleaning and siphoning out uneaten food and feces

Brushing, skin & coat care

No brushing. Check daily for wounds and missing scales, and scoop with a container rather than a net

Other care

Rinse filter media lightly in tank water. Never replace all filter sponges at once

Protection from predators

• A heavy, latched lid so cats cannot reach into the tank
• Protect losing fish from tankmates with a divider
• Large species eat small fish; do not keep them together

Foreign-body ingestion

Oscars and flowerhorns swallow gravel and ornaments. Place no decorations small enough to fit in the mouth; use fine sand or large rocks as substrate

Being stepped on

Do not step on a fish that has jumped out. If found on the floor, pick it up with wet hands and return it to the water even if dry, then wait several hours

Getting pinched

Fish get stuck in rockwork gaps or the canister filter intake. Fit a sponge on the intake and secure rocks so they cannot collapse

Falls

Collapsing rocks crush fish and crack the tank glass. Set rocks directly on the bottom glass and glue them so digging cannot topple them

Escape

Jumping through lid gaps is the most common escape. Use a heavy glass lid and seal gaps. Never release fish; it may violate the Invasive Alien Species Act or local ordinances

Safe release procedure

1. Hold your hand still underwater and wait for the fish to let go on its own
2. If it does not let go, gently support the fish's body underwater with your other hand
3. Slowly withdraw your hand from the mouth and lift your finger out of the water
4. With large species, use feeding tools or tongs instead of your hand

After the release

Rinse the wound under running water and disinfect. If redness, swelling or fever develops, suspect mycobacterial infection and see a dermatologist

What to tell the vet & what to bring

Species, body length, pH and temperature, ammonia and other readings, diet, date of last water change, photos and video. Transport in tank water

Checking consciousness, breathing & heartbeat

• Count gill cover movements (about 60–90 per minute at rest)
• If lying on its side or unresponsive, check the eyes and body color
• Immediately test pH, ammonia, nitrite and temperature

Stopping bleeding

• Fish bleeding is hard to stop underwater. First isolate and keep calm
• Give a 0.3–0.5% salt bath in clean water to prevent secondary infection
• If bleeding from the gills or it will not stop, consult the same day

Transport

• Add oxygen to a bag or container of tank water; keep dark and insulated
• Enough water in the bag that the fish cannot lie on its side. Use a foam box to hold temperature