Can't keep Black lancer catfish

[Viktor Jarikov]

Tried twice. First with one specimen. Second with 3. All from WetSpot, Oregon. Starts out fine. They grew from 1.5" to 4"-5" over some months. Fed very well. Die out of a blue. Feed one day just fine, if not too much, dead the next day.

Is there anyone else with a similar problem?

The only thing I could come up with is overfeeding. I've always had them with plenty other fish and they appear to feed too much on farm catfish pellets. Yet, IDK if this is simply their nature.

[Silurus]

What kind of water are you keeping them in?

[Viktor Jarikov]

KH ~5 degree, stable
GH ~5 degree, stable
pH 7.4, stable
temp varies seasonally from 70-72 F to 85-89 F, no heating, no cooling, in a pavilion type of a structure.

Water's clean. No NH3, no NO2, NO3 is 5 ppm. Continuous water change.

They were in a 240 gal tank that shares the same 1000 gal sump with other 240 tanks, all together containing a hundred of diverse fishes. All alive and well today.

When I lost the first one about 10 months ago, the water was much softer (1-2 degree) and not stable. Neither was pH stable. So I thought maybe the lancers are sensitive to that (whilst the vast majority of other fishes tolerated this ok). After I fixed that, I got 3 more black lancers but was met with the same result.

[Silurus]

Your pH is a little too high for black lancers. These are fish that come primarily from brown water habitats. These are typically habitats very near to peat swamps (blackwater habitats, where the pH can be as low as 3.5) where some admixture with white water (pH about 6) has occurred. Consequently, they do best with a pH around 5.

I have found that fish from such habitats (especially those from blackwaters) become very prone to infection when maintained as too high a pH.

[Proteus]

Farm catfish pellets? Be more specific what it entails

[Viktor Jarikov]

Your pH is a little too high for black lancers. These are fish that come primarily from brown water habitats. These are typically habitats very near to peat swamps (blackwater habitats, where the pH can be as low as 3.5) where some admixture with white water (pH about 6) has occurred. Consequently, they do best with a pH around 5.

I have found that fish from such habitats (especially those from blackwaters) become very prone to infection when maintained as too high a pH.

Gotcha. Much appreciate it, HH. I didn't know their habitat was that diffirent from most others. Would the same apply to Harlequin lancer care?

Farm catfish pellets? Be more specific what it entails

I offer a variety but the lancers appear to favor these the most: http://www.zeiglerfeed.com/finfish/freshwater/silver/ I've been feeding this kind of pellet to my fish for 8 years as one of the staples accounting for roughly 50% of their averaged diet. I currently keep about a thousand of fish so I go through five 44 lb bags every 1.5-2 months.

[Bas Pels]

Farm catfish pellets? Be more specific what it entails

Good point

In a farm, people want their animals, such as fish, t ogrow rapidly in order to produce much meat

Our aim is to have the fishes live for a long time, and there are cases where feeding the fishes a lot does shorten their lives. Generally speaking, I would consider food intended to be used on a farm as too rich for our aquarium purposes.

[Richard B]

I've not had problems keeping black or harlequin lancers. pH 6.6-7.2 generally, nothing special, good filtration & aeration, smaller set-ups with small dither fish or very different bottom dwellers (mochokiella). General aquarium foodstuffs plus shredded earthworms, minced prawn etc

[Viktor Jarikov]

... No NH3, no NO2, NO3 is 5 ppm. Continuous water change...

A major correction.

Today I've found out I've been erring pretty badly on my continuous water change. The nitrates are ~100 ppm. The number of fish and their size increased a lot along with the feeding but I forgot to keep checking nitrates for at least 6 months.

Even if this wasn't the main cause of the lancer's passing, it certainly didn't help.

[Annabellam]

Proper tank maintainance is of paramount importance. Lesson we keep learning all the time. Have also failed not once but several times but we have to keep learning and trying.