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Discus and BGK

21K views 47 replies 7 participants last post by  dylan94 
#1 ·
I originally had a thread about a discus aquarium, but I decided to start a new one because there were like 6 pages of posts and it has been a while since I posted on it. I was in South Africa for about 2 weeks. It was an amzing trip!

I've been back for about a week now and when I stoped by the LFS to get some things to 'rehabilitate' my tank since the person taking care of my tank didnt do a very good job. Im not being unappreciative! I do appreciat their effort. ANYWAYS.. So I saw some black ghost knife fish in an aquarium at feeding time. They were SO COOL. So I obviously went home and saved my tank, then I went to research the black ghost knife fish. Turns out their needs are almost the same as discuses needs. They aren't aggressive to othe species of bigger fish. They are also compatible with bigger tetras. That takes cardinals off the list:( Cories are supposed to be big enough to not fit in their mouthes. Also cories have spiny fins, so the BGKs usually leave them alone. So a 6 foot, 100+ gallon tank, with 8 discus, 1 black ghost knife fish, a school of cories, a school of tetras like black skirts. Maybe even a pair of dwarf cichlids, depending on the size of the aquarium. I want it so that there is ample space for each of the fish to be able to get away from the other species. I think six feet of swimming space is enough.
This is what aqadvisor said:
http://www.aqadvisor.com/AqAdvisor....AqSpeciesWindowSize=short&AqSearchMode=simple

I read that BGKs could be kept alone in a 55, so I think a 110g is fine... does anybody have an opinion on this setup.

I am actually getting close to getting this project started. I already started saving money, I am at 625$ after only a week or two!!!! I have a feeling my money wont be growing this fast in the future:( We are also almost done finishing the basement the tank will be in!!! HOORAY!:-D
 
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#2 ·
Hey, I wouldn't say don't try it but to be careful. The problem would be that BGK is nocturnal, and dicus are delicate fish. The BGK would stress them out at night, not that it would physicaly kill them or anything. Depending on the BGK's temperment it may nip at the discus, and the dicus would stress out very easily if its a full grown BGK. There would be plenty of room so that would not be the issue.Hope that helps your decision.
 
#3 ·
I plan on putting tons of plants in the tank, so the fish can hide from each other. I also plan on buying a5-6 inch juvenile bgk. I will feed the bgk bloodworms and brineshrimp. I know bgks like a place to hide during the day. Would plants and driftwood suffice or should I put some pcv pipes and caves type things too?
 
#4 ·
I would suggest getting a good lengthed PVC tube that will last him (12-14inches). And if your going for a natural look which i assume you are buy some rocks to make it appear as a cave. What i did is add river rocks to the ends so that you dont notice the PVC. As for my BGK he is very strict on his nocturnal nature lol, so as soon as I made this cave he loved it. Having a good hiding place will be helpful in reducing the stress, everything you mentioned would be the correct way to take care of him. What I would do after putting them together is to keep a good eye on both the BGK and the discus. See what effects if any they have on each other, its going to be expiremental remember that. And going back and reading through your stock list will be tight, you may want to wait on some more advice. But I would suggest trimming down some where because from what I know that sounds like it could be busy. Like I said I would wait for more advice I dont know much about discus personally, just the BGK. :)
 
#5 ·
My discus like to sleep on the very bottom of the tank, nestled against each other, in the back where it is heavily planted. Very curious, not sure if this is common. I would worry about a BGK cruising at night, possibly bothering them. I do have a late night pictus cruiser but he stays away from the plants, preferring to swim up and down the length of the front of the tank, where it's not planted. The pictus and his late night behavior is most likely why my discus sleep where they do. I know I wouldn't put a BGK in my tank, but that's just me.

PS. As much as I like my discus and want them to be comfortable rehoming the pictus isn't an option as he was my very first fish.
 
#6 ·
hmmm... interesting:)
If the tank is six foot, I can have it heavily planted on one side and barely planted to not planted on the other side. I read that bgks aren't aggressive towards other fish if they are of a different species. The bgk would probably not be aggresive to the discus, but i agree that his nocturnal habits may disrupt the discus and their sleeping habits.

-Aunt Kymmie- I think your discus sleep at the botttom in the plants because they probably feel safe there and because the pictus swims in the open at night. If bgks like to swim in the plants and at the bottom, then wouldn't the discus prefer to sleep higher up? Does anyone know if bgks swim all around the tank at night or do they stay around their territory and at the bottom?

Maybe not including a bgk might be a good idea, but they are sooo cool and I am pretty sure the discus would be fine, especially if there are eight of them!
 
#7 ·
BGK swim all over the aquarium, they can swim backwards as well as fowards. I think it may be best not to mix, because im pretty sure the discus will get stressed out. It is an interesting idea and almost seems like it could work, but sounds a little too risky.
 
#9 · (Edited)
Some divergent opinions expressed on keeping discus with knifefish; I must weigh in on the side of those who do not recommend it.

Aggression is only one of many considerations when deciding on what fish to put into a community aquarium--community referring to any tank that will house more than one species of fish. To be compatible, all fish in a community aquarium must share the same preferences for water parameters (pH, hardness and temperature), environment (plants, rocks, wood, caves, water movement, light), and behaviours must be compatible. We often think of the latter, which is where the aggression comes in, but infrequently do we consider the very important aspects of what the individual fish need in their environment to be stress-free and thus healthy.

The knifefish being considered is the beautiful black ghost, Apteronotus albifrons, that is found in sections of the Amazon basin. They occur in shallow, fast-flowing streams and rivers with soft substrates of sand and leaf litter. They forage for small prey during the night using their electrical fields. They are rarely found in still or deep-water habitats.

Discus come from very still waters, flooded forests being their preference during the flood season, or otherwise along the quiet banks of streams and rivers with thick vegetation, fallen branches, overhanging vegetation. Dimly lit, with minimal water movement.

I trust it will be obvious that solely in terms of their natural habitats, these two fish are not compatible. If the aquarium has sufficient filtration to create the faster water currents the knifefish require, the discus will be stressed by fighting currents during the day, and at night will have no rest from either this or the nocturnal ramblings of the knifefish. If on the other hand the tank is minimally filtered so the water movement is almost non-existent, the discus will be happier with that but the knifefish will be stressed by being out of its environment, and not only health issues could ensue but behaviour alterations as well. Which applies equally to the discus of course. Any fish under stress from its environment is likely to experience immune system weakness, leading to unsettled anxiety and probable disease.

I checked the link in the first post, and note that it does not recommend this grouping of fish for some good reasons in addition to the above. I didn't elaborate on the earlier mention of the nocturnal habits of the knifefish, but this is a serious consideration with discus and would in my view alone be sufficient to not combine the two.

Byron.
 
#10 ·
Yea Im going to have to agree that you shouldn't mix them. When you think about it they aren't compatible on behaviour level. Although I have never heard a ghostknife requiring a strong current? Even without that in consideration, the nocturnal behavior which I mentioned before would not be good for this dicus. And to add to that they use an electrical organ to navigate, and granted they aren't an electric eel that would probably cause problems as well. I would think the dicus would feel the pulse at night while the knifefish is exploring even if the knifefish doesn't physically come in thier space (stressing them out keeping them awake sort of speak). And between these two reasons I believe the dicus is just too delicate to keep with the ghostknife. I will ask my LFS sources about the current as that is something I havent heard before. My ghostknife does prefer the side of the tank with the filter outlet, so that sparks my curiosity.(I will post this in the correct thread when I find out whatever I may)
 
#11 ·
To respond earlier I consulted an article in the June 2009 TFH by Dr. Neale Monks on Knifefish in order to refresh my memory as I recalled reading it previously. Dr. Monks is specialized in the fields of marine biology and paleontology. Any of the online resources will obviously say the same thing, I trust Seriously Fish http://www.seriouslyfish.com/profile.php?genus=Apteronotus&species=albifrons&id=435 but there are others. Will be interested in what store people say. B.
 
#13 · (Edited)
There you are then; I know the fellow who authors that site, Matt, but we can't always agree on everything:lol:. I certainly do not recommend it for previously-stated reasons; that site does mention fast streams for knifefish and slow moving streams for discus, so the conclusion from those facts is obvious to me. I may check in with Jack Wattley on this, if anyone knows discus he does. B.
 
#14 ·
After reading all that, I do agree that discus and black ghost knifefish should not be kept together. Before, I was only thinking about the fact that bgks are nocturnal, whereas discus are diurnal. Because they are both native to different habitats and bgks can likely disrupt the dicus during their sleep as well as during the day. I guess, now I can keep cardinal tetras :) yay. Although bgks are very cool, I think I will exclude them from this project, however I do plan on keeping them in the future. Looks like I am back to my old stocking list ;)

BTW I was so excited today when my cories spawned again today. They spawned exactly one week ago and I only was able to get two eggs out of the aquarium. Two days ago, they both hatched and now I found 4 more. The ones that hatched are doing good and I think they are getting better at swimming. They seem as though they are wigglers at the moment. The thing that shocked me was that I only have two peppered cories. I thought they were two males but apparently I am wrong. Hopefully if they continue breeding I will be able to raise some fry to adulthood, thus the cories will be happier with a larger population. The female seems to have somewhat of a pouch of eggs on her belly that is constantly refilling with eggs. It is also cool how she holds the eggs between her two fins while it is fertilized and then she places it in the java moss :) Perfect place to put her babies!
 
#16 ·
I was wondering, if I want a low pH and very soft water and I am planning on using a reverse osmosis unit, can I just make the tank water pure RO water or do I have to absolutely add regular tap water. I have heard of cases where 0 hardness can lead to random pH drops and the water needs somewhat of a buffering capacity. Is this true or can I fill my tank with 100% pure water. Also, if I do need to add regular tap water do I have to get the exact measurments of water ratio or can I just do water changes by just adding RO water and then a bit of regular water. EX: I do a 50% water change. I fill up to like 2 inches below the top and then fill the rest with regular tap water?
 
#18 · (Edited)
I would suggest that this depends upon the fish you have in the tank, both what they are (the species) and if they are wild-caught or tank-raised commercially.

With no carbonate hardness to buffer the pH, the pH in an established aquarium will lower fairly quickly after the initial "settling in" period. My tap water is <1 dKH and <1 dGH, and the pH is 7.0 [they put soda ash in the water to keep the pH at 7, it is around 5-6 naturally]. My 70g and 90g aquaria have no buffering agents added, just straight tap water. The hardness is zero (GH and KH) and the pH is 5 or perhaps lower, my test kit only goes to 5. When I do the 50% pwc every week, the pH rises slightly, but not above 6; the lowest test kit I can find indicates 5 as the lowest colour, then 6 with nothing between, and the water is never at 6 so I can only assume it remains close to 5. These tanks have mostly wild-caught fish from Amazonia in the 90g and SE Asia in the 70g; they are vibrant, active, always spawning, so I must conclude they are happy and healthy.

In my 115g I have half a cup of dolomite in the filter; the hardness is steady (for months, even years) at 1-2 dGH, and pH is 6.0 to 6.4 with the usual diurnal variation that occurs in planted aquaria. I have a mix of wild-caught and tank-raised fish from Amazonia in this tank. Spawning is regular among most all the species.

All of the fish I have come from very soft acidic waters. We know that in their native habitat the hardness is so low is cannot be measured, or at the very most may be somewhere between 0 and 1 d, identical to my tap water. The pH of many of these waters varies from 3.5 to 5.5 depending upon the locality. I am speaking of the specific habitats of the species I maintain; there are streams in SA with harder and slightly basic water, but I always thoroughly research the habitats of any fish I intend to acquire so I know I can provide exactly what they require, and those in my aquaria are suited to my water parameters.

Fish and plants require minerals. Fish food provides some of these to fish, and the resulting waste provides some to the plants. We also use liquid fertilizer, root fertilizer, and sometimes enriched substrates, all of which add minerals for the plants. If you have hard or relatively hard tap water, mixing some in with the RO water for the initial filling of the tank can do no harm, and probably would benefit. Monitoring the pH weekly would indicate any lowering as would be bound to occur over a few weeks with a very low hardness, and then replacement water (during the weekly pwc) could be mixed to maintain a stable level, such as I have in my 115g. This avoids any sudden shifts, which is the danger; once a tank is biologically established and mature, it has a tendancy to remain stable even with the influx of water with a not too significant higher degree of hardness and pH. I would base this on the fish and their source.

Byron.
 
#19 ·
BGKs all have different temperaments, some will get along with small tetras, and some will kill anything you have in the tank with them. I would say that as long as the BGK you get is small, it will get along with large discus. But not small discus. My BGKs got along with the small school of tetras I had in my tank for about 8 months, until I forgot to feed them too long...:roll: Then there were no more tetras. BGKs will eat the eyes out of any fish that annoys them too much and is too big to swallow whole. You will probably never see your BGK's mouth fully open unless they get really ticked off. They can easily swallow a tetra and more whole. So you could divide the tank to see how the BGK acts for a while, then if it's OK remove the divider. Unless you want the focus to be on the discus, in that case you should only get the discus.
 
#20 ·
I dont think I will include bgks in my tank anymore, but thanks for trying to help Freddy :)

As for the pH and stuff. I know I am planning on keeping only soft acidic water loving fish. Therfore I will probably add like a gallon of tap water for every 50 gallons of RO water. Does this sound too low. I plan on letting the tank settle in for about a month without any fish, closely monitoring the pH and hardness just to make sure it is stable.

I wanted to mainly stick with fish that occur in the wild with discus. Does anybody (Byron) know which tributaries or rivers discus are usually found in, in Amazonia. Also, which other fish such as tetras and catfish and dwarf cichlids are usually found in the same rivers? I want to include gb rams and neon tetras anyways, but there might be some nice tetra and nice dwarf cichlid that I can choose instead that discus would normally live with in the wild.
 
#21 ·
Dylan, this is a major topic.:blink: This will be a real overview.

Most all discus available now are raised by breeders; the many colour varieties have been developed from the wild stock over many years through selective breeding. But I am one who still feels the fish will do best when their ancestry is understood and their habitat replicated as much as possible, so we are on the same wavelength. You cannot eradicate millions of years of evolutionary development by a few decades of tank rearing.

All discus belong to the genus Symphysodon, and although there is some disagreement as to the actual species, everyone agrees there are three. Symphysodon aequifasciata Pelligrin 1904, S. discus Heckel 1840, and S. haraldi Schultz 1960 are the scientifically recognized valid species; the variant "species" names are recognized as synonyms for one of these three.

S. aequifasciata occurs in the western Amazon River basin in Brazil, Columbia and Peru. S. discus occurs in the lower Rio ***** basin, and S. haraldi is found in the clearwater lakes and rivers in areas of the Amazon River basin in Brazil, Columbia and (possibly) Peru. The species do not overlap, that is, each is endemic within their respective watercourses.

Given that your discus will most probably not be wild-caught [see * below], you could ascertain the ancestral species and build the aquarium accordingly, or more easily simply select fish from any rivers known to be discus habitat regardless of the species. Or a third and easiest method, select fish that occur in identical habitats in terms of water parameters and environment. This latter consideration will be constant either way: very soft, acidic and warm; slow-flowing streams, thick with plants, dim light, bogwood, etc. Tankmates will have to be compatible, which leaves out neon tetras since Paracheirodon innesi occurs in cooler streams than any discus. On the other hand, the cardinal tetra, P. axelrodi, is found throughout the Rio ***** basin in identical habitats to discus. The German or common Ram, Mikrogeophagus ramirezi, would never be found with discus, but is an admirable tankmate because it needs basically identical water, and it tends to remain close to the substrate (like most dwarf cichlids from SA) while discus prefer mid-tank. Hatchetfish on top would be compatible. And Corydoras sterbai (one of the few corys that can tolerate the warmth), Farlowella, or the Whiptail are admirable other catfish species--and the last two are incredible algae eaters.

*Being in Quebec, you could obtain some from Oliver Lucanus at Below Water in Montreal; he has wild-caught S. tarzoo [green discus] from Tefe, Brazil, included in his latest fish list this week. This is an example of the "disagreement" over species I mentioned above, S. tarzoo is officially recognized as a synonym for the valid species S. aequifasciata.

How's that for starters. B.
 
#22 ·
I was tinking of having a few school of tetras, 8 discus, 2 german blue rams, a shoal of corydoras sterbai and a school of hatchets. For the tatras, I was thinking cardinals, black neons, rummynoses and glowlights. I like the look of smaller colourful tetras like the ones I mentioned with discus.

I want to completely cover at least half of the substrate in a grassy ground cover type plant. Do you recommend any plants for that? This tank is going to be gorgeous.

I read somewhere that the recommended ratio of RO water to tap water is 3 to 1. That is 25% tap water. I think that sounds more reasonable than 1 to 50... what do you think?
 
#23 ·
* I meant to say 50 RO to 1tap and 3 RO and 1tap... just to clarify :)
 
#24 ·
I've not had to use RO so I will leave all that for those who have. Once you set up the tank, without the fish of course, you can experiment with the water to get it where you want the hardness and pH, then work out the amounts for water changes and you're set.

I prefer not suggesting fish to others because it should be what you want, so I only point out troubles if I see them. And I don't here. But I would just comment that 3 tetra species have similar appearance, and you might think about that. Cardinals yes; instead of glowlights maybe a different shaped tetra for contrast and colour, one of the Hyphessobrycon "rosy tetra clade" species, check the fish profiles sectio under characins for lots of examples. I think almost every regularly-available tetra (and some not so regularly availble) is there now. You may get other ideas from those.
 
#25 ·
I have redone my stocking list slightly:
- 8 discus (symphysondon aequifasciatus)
- 3 yoyo loaches
- 1 farlowella
- 8 corydoras sterbai
- 10 cardinal tetras
- 8 black phantom tetras
- 8 emperor tetras
- 8 bleeding heart tetras
- 8 marbled hatchets
- 3 german blue rams
- 40 cherry shrimp !!!yay!!!
Do you think that is over stocked for a 112 gallon, 6 foot tank?

Aqadvisor says: http://www.aqadvisor.com/AqAdvisor.php?AquTankName=&AquListBoxTank=Choose&AquTankLength=72&AquTankDepth=20&AquTankHeight=18&AquListBoxFilter=Choose&AquTextFilterRate=N%2FA+&AquListBoxFilter2=Choose&AquTextFilterRate2=N%2FA+&AquFilterString=snail&AquListBoxChooser=Nerite+Snail+%28Nerita+sp.%29&AquTextBoxQuantity=&AquTextBoxRemoveQuantity=1&FormSubmit=%3C+Remove&AquListBoxSelected=1+x+Nerite+Snail+%28Nerita+sp.%29&AlreadySelected=200909300058%3A8%3A%3A%2C200909300078%3A3%3A%3A%2C200909300246%3A3%3A%3A%2C200909300071%3A1%3A%3A%2C200909300039%3A10%3A%3A%2C200909300021%3A8%3A%3A%2C200909300067%3A8%3A%3A%2C200909300025%3A8%3A%3A%2C200912051331%3A8%3A%3A%2C200911082326%3A40%3A%3A%2C201002031346%3A1%3A%3A&FilterMode=Display+all+species&AqTempUnit=C&AqVolUnit=gUS&AqLengthUnit=inch&AqSortType=cname&FilterQuantity=2&AqJuvMode=&AqSpeciesWindowSize=short&AqSearchMode=simple
I was also wondering about silver dollars. They aren't very colourful, but they are shiny and it must be cool watching a school of those swim around. I decided against them however, because, they are big, might stress out my discus and are not very colourful, which is what I want. Maybe I will include them in an angel tank one day :)

I calculated my water changes percentage:

1 degree is around 18ppm so my water is 200ppm (11 degrees) if 3/4 of my water is 0ppm/0dgH, and 1/4 is 200ppm/11dgH, the outcome of mixing them would reslut in 50ppm(around 3dgH). Do you think 3degrees sounds good or should I try to go lower? I know these numbers might change, when I am actually setting up the tank, so like you said I will have to experiment with this. I wanted the water to be around 5.5pH. Will the pH drop that low with a low enough dgH?
 
#26 ·
I have redone my stocking list slightly:
- 8 discus (symphysondon aequifasciatus)
- 3 yoyo loaches
- 1 farlowella
- 8 corydoras sterbai
- 10 cardinal tetras
- 8 black phantom tetras
- 8 emperor tetras
- 8 bleeding heart tetras
- 8 marbled hatchets
- 3 german blue rams
- 40 cherry shrimp !!!yay!!!
Do you think that is over stocked for a 112 gallon, 6 foot tank?
Yoyos do much better in a group, rather than a trio. I always like to see five or more when it comes to yoyos. Loaches love inverts and shrimp will make for some pretty tasty snacking for the inquisitive yoyos.
 
#27 ·
I think dwarf tears or something will form a nice carpet and will grow on driftwood and rocks.

If you decide to change your stocking list at all, angelfish are from the Amazon area and will peacefully coexist with discus.
 
#28 ·
You definitely don't want silver dollars in your discus tank. Silver dollars would quite literally eat your discus out of house and home as they'd eat all of your plants. I'm also not sure how well the cherry shrimp would do at those elevated temperatures (plus they'd likely get eaten by the larger fish like the rams, loaches and the discus themselves).
 
#29 ·
I have decided to switch out my yoyo loaches and shrimp for some other fish. The yoyo loaches were taking up a lot of stocking space... I will replace them with 4 sparkling pygmy gouramis and maybe a species of apistogramma. At my LFS they keep angels, apistogramma cacatuoides and apistogramma agasizzi with their discus. I tried both of those apistos on aqadvisor but it said that they will be too aggressive to coexist with cardinals,bleeding hearts, black phantoms and emperors. Do you think that is the case or would the tetras just quickly swim away from them?
 
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