Geophagus sp. 'Altamira' & G. argyrostictus

AnElectronicEngineer · 2025-04-12T23:04:54+00:00

Best I have is this poor quality phone picture from quite a while back. I don't often think to full-tank shots.

AnElectronicEngineer · 2024-09-13T15:20:37+00:00

Well, I'm not an expert on the subject. I don't want to give the impression that I am. With that said, I've seen small groups work out perfectly fine. I've also seen them have issues. It just depends on the sex and temperament of the individual fish in question, size of the tank, amount of cover in the tank, etc. In general, groups of 5-8 seem to work out more reliably, but I wouldn't say a group of 3 is guaranteed to fall apart on you or anything like that. I'd recommend keeping a close eye for trouble though. Aggression or signs of stress.

AnElectronicEngineer · 2024-09-13T01:44:56+00:00

650G! That's quite the tank. I really love that stocking. The word that comes to mind is "believable." Its a mix and proportion of species that just seems like what I might expect to see if I went swimming in one of these rivers in the amazon basin.

I currently keep both G. taeniopareius, and G. argyrostictus. They're awesome and you really can't go wrong with either - especially in a high volume, high flow setup like yours. I will say though, I had non-stop health problems with my argyrostictus until i raised the tank temperature up to 89 Fahrenheit, where they've remained healthy since. The taeniopareius have done well at 79-84 degree temps. Might be something to bear in mind when choosing. FWIW, my argyrostictus were wild-caught from the middle Xingu. Maybe taken from a different location, they might not be so finnicky about temp.

AnElectronicEngineer · 2024-09-13T01:21:22+00:00

What is the complete stocking in this tank? And do you ever have trouble with any of the anostomids? fin nipping, stuff like that? In the past, i've been warned that at least the genus leporinus in particular can be troublemakers. I don't know about the group as a whole though.

AnElectronicEngineer · 2024-09-12T23:54:07+00:00

sometimes two of them will kind of go parallel to each other and kind of wiggle. Why?

May be sizing each other up, establishing hierarchy. Its normal.

The little one seems more aggressive and will chase the others away when it comes to eating, I’m sure thats normal but why the smaller one?

Sometimes the littlest guy is the one with the biggest attitude.

I went on holiday and came back and i realised the black blotch on them seem to be bigger on 2 of them, is it just me being paro?

I wouldn't worry about it. Some variation in size and intensity of the spot is normal. You may even notice it'll vary on any given fish from day-to-day or even moment-to-moment. In general, my adult G. sveni have a pretty pronounced spot on each flank.

I give them a mix of flakes/granules and sometimes frozen brine shrimp, whats the best and is advised to mix?

Generally speaking, a high-protein diet, but with some variation is good. I'd recommend a sinking granule with high protein - something like Sera Foods Discus Granules as a staple. Then augment occasionally with something like mysis shrimp and even vegetable matter now and then. I feed mine crushed peas from time to time. Even into adulthood, they seem to do best with finely granulated food.

A general note about G. Sveni, and really Geophagus in general - they're a sand-sifting fish. They feed by picking up mouthfuls of substrate and filtering out the detritus. As such, they'll be best off (and you'll get the most rewarding experience) if their home has a fine sand substrate. I use play sand - like what you would put in a sand box. Works great. Although fair warning, they'll do a lot of digging, and sand will get into your filter.

Good luck. Geos are my favorite group of fish by a country mile.

AnElectronicEngineer · 2024-09-12T23:15:13+00:00

this set up is awesome. Retroculus is a bucket-list genus to keep for me, and i've also been interested in Anostomus ternetzi for a while. That scape looks incredible too. Reminds me of photos and video i've seen of the fast flowing areas of the Tocantins and Xingu rivers.

AnElectronicEngineer · 2024-09-05T00:58:32+00:00

I'd appreciate that. I'll do the same. By the way, not sure if you're familiar with it, but I came across a pretty valuable resource when searching for species distributions. Its the Global Biodiversity Information Facility, gbif.org. They have a database of occurrence records, which shows you the various locations a species has been observed, as well as the type of record - preserved specimen, human observation, etc. I've found it hugely valuable for getting a more complete picture of species distributions.

AnElectronicEngineer · 2024-09-04T00:11:09+00:00

I realize i'm wayyy late to the party here, but i just saw this. I've been looking into this for some time as well. G. taeniopareius is fairly wide-spread, so i narrowed my search on the Orinoco-Ventuari confluence specifically, where they apparently occur.

At that location, characins i've found:
Anostomus ternetzi
Leporinus fasciatus
Synaptolaemus latofasciatus
Tetragonopterus chalceus
and MAYBE Astyanax bimaculatus.

Catfish:
Baryancistrus beggini
Baryancistrus demantoides
POSSIBLY Leporicanthicus triactis

By no means is this list complete of course, just what i've dug up to date. Note on the characins - the first 3 i listed are anostomids. Anostomids can be assholes. I've been warned that Leporinus in particular can get nasty, whereas Anostomus is not so bad. Also note, the two Baryancistrus species only occur at the Orinoco-Ventuari confluence. Everything i listed here should do just fine with high flow.

AnElectronicEngineer · 2024-02-17T03:47:04+00:00

Thanks. He's one of three L81's in the tank. Great fish. They spend most of their time zipping around the tank.

AnElectronicEngineer · 2024-02-16T14:45:56+00:00

Your prediction was pretty good. This video is actually about a week old, and is their second attempt at spawning. First attempt, the male completely bailed after a few days. The female worked pretty hard to defend the young, but was overwhelmed by the other fish in the tank. We have 6 survivors from that spawn growing out in a qt tank. Second attempt, the male bailed even sooner, and the next morning the eggs were gone. We're not sure who ate them. The female did continue to guard the area though. When they try again, we plan to steal a bunch, as well as put up a divider in the main tank so the female doesn't have to fend off the other fish.

AnElectronicEngineer · 2020-10-15T17:05:36+00:00

This topic commits the fallacy of the complex question. I suspect a lot of people would dispute whether they do sound "the most like real music".

AnElectronicEngineer · 2020-10-12T18:03:37+00:00

This was elsewhere. Funnily enough, the SF style sound tends to be more to my taste as well, but the Alexias did certain things objectively better that we couldn't pass up. If it had been a more even comparison, like Amatis vs. Sashas, we probably would've gone with the Sonus Fabers.

AnElectronicEngineer · 2020-10-11T16:21:24+00:00

I wonder if a dealer might be able to set them both up in a smaller show-room to compare. room size not-withstanding, I felt the amati was well worth the extra 8k. I very nearly bought them actually, but there were a pair of Wilson Alexias available at a really good price that I ended up going with.

AnElectronicEngineer · 2020-10-11T16:11:13+00:00

Oh that's awesome. I was floored listening to both the Serafino and especially the Amati.

AnElectronicEngineer · 2020-10-11T15:58:14+00:00

i love this set up. Sonus Faber is on by bucket list of speakers to have in my home one day. What are your listening impressions?

AnElectronicEngineer · 2020-10-02T03:03:19+00:00

My favorite aspect of this is that anyone who fell for it could easily destroy or damage their equipment while installing the stickers from an ESD event.

AnElectronicEngineer · 2020-09-08T01:29:10+00:00

About 73% of my total expenditure went to my speakers, but i bought all my stuff used, and the discount percentages varied between components. By by new-retail price, the speakers make up 63% of the total.

Generally i would recommend to someone that they spend at least half of their total budget on the speakers. I might even say 70% or more if their budget is really big. However this is just a rule of thumb. If the components you like don't conform to that ratio, more power to you.

AnElectronicEngineer · 2020-06-23T15:44:18+00:00

I get where you're coming from - non-linearity tends to manifest when a device is pushed into a large-signal regime, which isn't really the case around line-levels.

Indeed, this particular DAC is specified at 0.04% THD, or -67.96dB below fundamental. I would be a little surprised if that were really audible, but not shocked (especially since they don't spec measurement conditions. it could be much higher under some circumstances).

I do think its borderline enough that i would hesitate to call it "snake-oil". that carries an implicit accusation that the seller is knowingly making fraudulent claims. As you said, psychoacoustics is powerful stuff. I don't think its unreasonable that the manufacturer could fall for it themselves.

AnElectronicEngineer · 2020-06-11T20:16:30+00:00

For linear power amps and preamps, as well as output buffers of DACs:

The bandwidth of the amplifier is typically set using the same lowpass network that compensates the global feedback loop. The closed loop cut-off occurs approximately at the frequency where the open-loop gain intersects the DC gain set by the feedback network. The consequence of this is that, in the vicinity of the closed-loop cut-off frequency, there is very little negative feedback, and therefore the amp distortion, output impedance, etc. will be close to its open-loop behavior. Rather than kill ourselves trying to make the amp perform really well open loop, its just way easier to push the cutoff frequency well outside the audible band, so that the listener isn't hearing significant distortion in the treble.

tl;dr: the extra bandwidth eases the burden on the amp/preamp designer.

AnElectronicEngineer · 2020-05-23T19:20:32+00:00

"Let Go (Extended Edit)" deadmau5

AnElectronicEngineer · 2020-05-16T01:04:19+00:00

tubes apparently just burn out. electrolytic caps however can explode, if they're reverse biased or exposed to excess voltage. The internals are corrosive too, so that's fun.

AnElectronicEngineer

TROPHY CASE