Beiträge von FranciscoB

    So they don't eat the plants too much (hopefully)...

    Nori (on clip), frog bit (in floating corral).

    All plants and decorations natural. Relatively recently set-up new tank.

    8 adult Metynnis, 3 species (altidorsalis, lippincotianus, maculatus).

    10 different plant species (frog bit meant to be eaten).

    Hi Ralf,

    I am not familiar with that particular product, nor have tried other commercially available humic substance formulations. However, I do put a few magnolia leaves in all my tanks (year round, from my backyard). I am not certain they help, but they do produce a slight tint in the water, and my fishes are healthy and go through breeding motions (including mock breeding and displaying) frequently. I replace the leaves every other week. I also have large pieces of driftwood in all tanks, but as yours, they probably don't release much any more.

    I do believe the addition of the leaves brings positive effects, even if they may not be dramatic and of I cannot fully demonstrate the beneficial effects. Conversely, I have not noticed any deleterious effects.

    I am not certain of what is a " 36W UVC clarifier", which you say you have "currently in continuous use, has any effects on the humic substances, similar to drugs or water conditioners."

    I assume it is some sort of ultraviolet device?, but I am uncertain why is deemed necessary. Regarding medicines, those should be used rarely or very hardly often so medicine removal needs should also be rare. Regarding water conditioners (dechlorinators?) Those may not need to be removed at all.

    So I cannot not answer any of your questions, except to say I do use leaves (thought to release tannic substances) and believe them to have been beneficial.

    Good luck!


    Beautiful tank!

    The way I see it, it is a personal choice, itself dependent on what else you have going on.

    For myself, I consider that few plants require the CO2, most can benefit from it but don't strictly need it, and yet others couldn't care less less (grow ok even if slow without it).

    And again, for myself, getting the CO2, constantly having to tweak things, and dealing with pH fluctuations, is just not worth the hassle.

    I would use weekly fert and occasional root tabs, and call it done.

    Good luck!

    Thank you!

    I don't know for sure how it has worked for me, but I can say that it has worked twice, in two different tanks, and this has been going on for nearly 4 years. As I said earlier, I am currently setting up a third tank (6 feet long), where all silver dollars will be consolidated. There will be a total of 12 fish, 4 species of Metynnis.

    The tank has been running for 2 weeks now, has been planted (with the same plant species as I had success before + 4 additional species which I will be trying out with the dollars). I am letting the plants get a good hold, become well established, and only then will introduce the Metynnis. Prior to that, some Otocinclus, Corydoras and some Colombian tetras (H. columbianus) will be introduced.

    I have some 'Hypotheses' as to how to explain my apparent success with Metynnis spp. in planted aquaria. I don't know which of these explain more, but I think all play some role -

    Hyp. 1 - Some plants are unpalatable to them, hence they don't eat them or not beyond trying it.

    Hyp. 2 - For whatever reasons, some of my individual fish don't seem to eat the plants (at least not much), and other fish can 'learn' from them. I should be able to use 'good role models' to teach new fish. My fish have come to me at 3 different times, the oldest (26 year olds) arriving first.

    Hyp. 3 - Some plant eating is OK (on certain specific fast-growing plants), so long as it is not excessive and the plants can grow fast enough so as not to decline over time, thus maintaining themselves and looking good.

    Yet another set of possibilities is related to how I feed them. I provide a varied diet, including 7 different types of pellets and flakes (insect & veggie based), frozen (insect, crustacean + Spirulina enriched), seeds and grains (sunflower + garbanzo), veggies (cucumber + nori). In addition, I provide frogbit + duckweed as permanent floating plants for food.

    The truth is I don't really know the secret, but are enjoying some success, and I am trying to understand it and attain it once more in yet another tank.

    Photo - Nori for breakfast!


    There are several plants that I have been able to see thrive with my Metynnis spp. silver dollars, including my only specimen of M. altidorsalis (an adult male). I hope to get one or two female altidorsalis in the near future.

    In the photo, he is in the foreground, the two other specimens are male M. lippincotianus. Floating plants (in floating corral) are Salvinia, place there as food, and replaced regularly. Rooted plants (not food) are Cryptocoryne wendii 'bronze' on floor mat at left, Microsorum pteropus (on wood, -but can be left floating), and Hygrophila sp. (at left, also could be left floating). In the back, there is some Bacopa monnieri, but they do eat that plant too much.

    The same fish when he was in my other planted silver dollar tank, together with M. maculatus, and L. lipponcotianus. Same plants, plus rooted, Cryptocoryne usteriana. He is at left, bottom, partially covered.

    In all his splendor ..

    I am now in the process of consolidating my 2 Metynnis tanks into a single, larger planted tank, currently being set up. I will soon show it here!

    Good luck!

    For Central American tetras, there are several Astyanax species. Unfortunately, as far as I know, the only commonly available in the market are Astyanax fasciatus, and the blind tetras A. fasciatus mexicanus. Both of these are quite able of fending for themselves (usually) and are active enough to make a nice display. Other species are just never available.

    Sorry to hear of the problem, Maggi.

    I don't know what the issue may be be but it is possible that as you say, the hard water may be causing problems. It is worth considering further. However it is strange that the fish appear well for a long time, and then die without clear reason, within a short period of each other.

    Another issue I would consider would be to provide a more varied diet, specifically including other types of animal food, such as cut-up small earthworms. It may be that a higher variety may do them better. Nothing wrong with the mosquito larvae, but more 'meaty' foods may improve conditions? A self sustaining worm bin is easy to set up.

    I hope you figure it out, and good luck anyway!

    Absolutely beautiful!

    Thank you so much for sharing. Would you care to describe your setup in more detail? What are the plant species you are using (very successfully, by the way)?

    What tetra species is the group sporting an oblique line trough the tail and part of the body? Is it a species of Moenfhausia?, or a small Triportheus?

    Again, gorgeous setup! Thanks.

    [I just realized I did not translate to German...]

    Hi Daniel,

    Lucky you!

    That sounds like a wonderful tank!

    A few comments on the Tapajos biotope and the fish selection:

    C .. regani is quite common (that's my understanding) and a setting in which they are prominently represented doesn't have to be Tapajos-specific.

    H. pulchripinnis are also quite common and are primarily associated with the Tocantins Basin, not necessarily the Tapajos.

    I love your choice of lemon tetras (H. pulchripinnis) as the numerous schooling fish that complement the rest of the setup. I love lemon tetra and currently have a smaller school (15 or so) in my tank that is considerably smaller than you plan on. Although Regani pike are much more peaceful than other species in the genus, they still grow tall (14cm or so) and I'm afraid some of the lemon tetra won't get past them unless there are plenty of rocks and wooden hiding spots , but also with these hiding places. That would be my only consideration regarding the stocking.

    My only other comment would be to add some plants that may be attached to the tops of branches (thicker ones, not thin ones), although I realize that this would be difficult to do in true Tapajos fashion. But it would provide refuge for the little tetras and improve the overall aspect of the setup.

    Sounds good! I look forward to seeing it. Good luck with that and thanks for sharing.


    Hi Daniel,

    Lucky you!

    That sounds like a wonderful tank!

    A couple of comments on the Tapajos biotope and the fish choices:

    C.. regani is quite widely distributed (that is my understanding) and a setting featuring them prominently does not need to be Tapajos-specific.

    H. pulchripinnis are also rather broadly distributed, and mainly associated with the Tocantins basin, not necessarily the Tapajos.

    I love your choice of lemon tetras (H. pulchripinnis) as the numerous schooling fish to complement the rest of the setup. I love lemon tetras and currently have a smaller school (15 or so) in my tank, which is considerably smaller than what you are planning. Although regani pikes are considerably more peaceful than other species of the genus, they still get large (14cm or so) and I fear that some of the lemon tetras may not be passed by them, unless there is a lot of rocks and wood hiding places, but even with these hiding places. That would be my only consideration about the stocking.

    My only other comment would be to consider adding some plants, perhaps attached to upper parts of branches (thicker, not thin ones), although I realize this would be difficult in a true Tapajos manner. But It would add refuge to the small tetras and help enhance the overall aspect of the setup.

    Sounds great! I look forward to seeing it. Good luck with it and thanks for sharing.


    Only one animal, or as a group in a very large tank. In their natural habitat, adults are schooling fish, and in addition to that, they are migratory as part of their reproductive seasonality. They do so in large shoals.

    Perhaps the INTRAspecific aggresion we see in aquaria (almost always too small) does not occur as much in nature, or, alternatively, it may play a role in the social context of migratory behavior.

    But in commonly sized aquaria, more than one specimen will almost always result in a lot of picking and hierarchy fights, usually to the demise of a lesser specimen (small or less self assured).

    It is great that these fish exhibit little to no- INTERspecific aggression, and generally are rather tame towards other fish, both larger and smaller. Mine (20-25cm) is very docile (though seeks food very aggressively) and friendly, and a delight to have (meet him/her below). She/he likes to be pet on the top of the head.

    Hi Axel,

    +1 about the (otherwise good pictures) not showing well the issue.

    In my opinion, the exophthalmy (googly eye) may not be related at all with the tumor-like ailments, nor the flashing that you are observing on your fish. I think they are separate issues happening at the same time.

    Regarding the growths, I am afraid that indeed, it may be what is often called 'fish tuberculosis'. Very likely, this came into the tank with the recent introduction of the platys, even if those may not have displayed it. I say that, assuming that your aquarium had the rest of the fish for a long while in good health, prior to the platys; I don't know the history so I may be wrong. My opinion is that 'fish tuberculosis' is a general term used to describe ailments caused by actually a number of different agents, and not a single causing microorganism. If viral, there is no effective treatment. If bacterial, it should be treatable but you may need a combination treatment, as the actual agent is not known to you.

    Regarding the googly eyes - In my experience this can occur from either a physical injury to the eye (somewhat uncommon), but is more frequently due to chronically insufficient water changes leading to accumulation of nitrate to high levels (beyond 20ppm). The fact that two fish showed it argues against physical injuries separately on each. Again, you know the history of water changes and nitrate in the tank, but I would recommend to check that. I have been able to improve the health and appearance of googly eyed fish I have rescued, just by providing excellent water quality via frequent and large water changes as a routine (for me, no less than 50-70% weekly). It takes months but it does recede, even in cases of whitish films over part of the eye.

    A different observation is that the ideal conditions for long term health of the altum and Manacapuru angels and that of the platys are at odds. Softer, lower pH versus harder, higher pH. It is true that both are adaptable (especially the platys), but they are not an ideal combination. Something to think about for the long term. Better to look for vivid colors among more compatible species.

    I hope others are able to better diagnoses, especially treatment suggestions. Good luck!