My Super Red Arowana is currently 42 cm long.
I’ve been keeping it for almost two years now — when I first got it, it was about 20 cm.
Over the past 45 days, the tail fin, dorsal fin, and to a lesser extent, the anal fin, have shown signs of fraying and erosion.
I’ve posted several photos showing the progression of this condition during these 45 days.
At first, I thought it was mechanical damage, because I have never observed any inflammation at the edges, nor any white patches, rot, or bruising along the torn areas.
The water parameters are good:
Nitrite and ammonia are both zero.
Nitrate is always kept below 25.
The fish is kept together with two stingrays (approximately 30–35 cm in size), and they have always coexisted peacefully.
TDS is consistently maintained between 280–300.
pH is between 7.4–7.6 (currently 7.5).
Water temperature is maintained between 28–28.5 °C.
After this problem appeared, I reduced the sump pump flow by 20%, bringing it to about 5–6 times the tank volume per hour.
The Eheim 2217 canister filter has also been turned off for the past three weeks to eliminate any extra water movement in the tank.
The filtration media—mainly Seachem Matrix and Bio Block—are in excellent condition.
I perform 30% water changes every 7–8 days using dechlorinated water with matching TDS.
I don’t add bacterial supplements very often—maybe that’s part of the problem—but I believe there’s already a sufficient bacterial colony in the system.
The fish’s main diet consists of shrimp, though it occasionally eats some high-quality dry food (mostly Tetra brand).
It generally doesn’t like dry pellets very much.
At the beginning of this issue, it lost its appetite (which, as we know, Arowanas sometimes do for a week or so), but now its appetite is excellent—it easily eats two shrimp pieces about 4–5 cm each when chopped up.
The tank size is 180 × 60 × 55 cm, with a sump of about 100–120 liters, bringing the total water volume to approximately 700 liters.
Finally, I should mention that I don’t have a proper quarantine tank suitable for an Arowana of this size, so any potential treatment would have to be done in the main tank alongside the two stingrays.
Do you think this could be chronic fin rot?
I can feed it Seachem Kanaplex mixed with Focus and shrimp, so it ingests the medication.
Alternatively, I could add Melafix or Ocean Free 0 Arowana Disease treatment directly to the tank water at the same time.
These options seem reasonable to me if this issue is indeed fin rot.
I’ve been keeping it for almost two years now — when I first got it, it was about 20 cm.
Over the past 45 days, the tail fin, dorsal fin, and to a lesser extent, the anal fin, have shown signs of fraying and erosion.
I’ve posted several photos showing the progression of this condition during these 45 days.
At first, I thought it was mechanical damage, because I have never observed any inflammation at the edges, nor any white patches, rot, or bruising along the torn areas.
The water parameters are good:
Nitrite and ammonia are both zero.
Nitrate is always kept below 25.
The fish is kept together with two stingrays (approximately 30–35 cm in size), and they have always coexisted peacefully.
TDS is consistently maintained between 280–300.
pH is between 7.4–7.6 (currently 7.5).
Water temperature is maintained between 28–28.5 °C.
After this problem appeared, I reduced the sump pump flow by 20%, bringing it to about 5–6 times the tank volume per hour.
The Eheim 2217 canister filter has also been turned off for the past three weeks to eliminate any extra water movement in the tank.
The filtration media—mainly Seachem Matrix and Bio Block—are in excellent condition.
I perform 30% water changes every 7–8 days using dechlorinated water with matching TDS.
I don’t add bacterial supplements very often—maybe that’s part of the problem—but I believe there’s already a sufficient bacterial colony in the system.
The fish’s main diet consists of shrimp, though it occasionally eats some high-quality dry food (mostly Tetra brand).
It generally doesn’t like dry pellets very much.
At the beginning of this issue, it lost its appetite (which, as we know, Arowanas sometimes do for a week or so), but now its appetite is excellent—it easily eats two shrimp pieces about 4–5 cm each when chopped up.
The tank size is 180 × 60 × 55 cm, with a sump of about 100–120 liters, bringing the total water volume to approximately 700 liters.
Finally, I should mention that I don’t have a proper quarantine tank suitable for an Arowana of this size, so any potential treatment would have to be done in the main tank alongside the two stingrays.
Do you think this could be chronic fin rot?
I can feed it Seachem Kanaplex mixed with Focus and shrimp, so it ingests the medication.
Alternatively, I could add Melafix or Ocean Free 0 Arowana Disease treatment directly to the tank water at the same time.
These options seem reasonable to me if this issue is indeed fin rot.
