At What Point Do I Seperate My Bgkf

[croggy]

I bought a BGKF (Black ghost knife fish) about a month ago for ym tetra tank

the guy at the fish store recommended him for just that purpose( the git )

after doing some research i have discovered that the BGKF finds tetras very tasty once he gets big enough to eat them

so my question is at what size will he become a threat to a fully grown tetra?

 

[mattlee]

i would remove it now as there is no point in keeping him in that tank. general rule is as soon as a fish can fit a fish in its mouth it will eat them if its that way inclined

 

[croggy]

yeah but it means buying another tank and moneys tight so need time to gather funds

thats why i was woundering about size?

i've contacted some people on the net who have BGKF with smaller fish and there simple reply was that they just got lucky and it never took any interest in eating their other fish

well to be honest i don't want to wait to see if i get lucky but at the same time i also need to put the funds aside first

so if there is any one who could give me a rough size to work with i would v.much appreciate it

thanks again

 

[elisew]

It's a bit like asking 'how long is a piece of string?'

I think Matt has answered your question in the best way it can be answered, it's not a case of how long have you got, it's more a case of if your other fish will fit in it's mouth then it's likely they'll get eaten so, you have one of 2 options really.....either rehome the knife fish or take the risk of the other fish being eaten.

I fully appreciate that there are times when funds aren't available as we all do but the decision about taking a risk ultimately lies with you.

 

[james_fish]

It has been known but only the bigger Tetra's eg. Congo's.

As for tank size you'll need a decent size. Just to give some idea, Matt is planning on keeping his in a 6 footer! these fish can grow anything up to 20"! So you'll need at least a 5 footer. So it really might not be worth you keeping this fish unless you are happy with paying a decent amount for big tank.

But yeah, i'd immediatly get rid of it unless you plan on upgrading.

James

 

[nmonks]

Black ghost knifefish are most worm and insect larvae eaters, and while they do eat small fish, they do so opportunistically. As others have said, on many occasions they ignore smaller fish, presumably where they're well fed on foods they like. Starvation is a common problem with black ghosts, especially when they're kept alongside loaches and catfish. Under such circumstances, who can blame them for eating a few neons if that's what they need to do to stay alive?

There are other reasons to review your aquarium though. Black ghosts need relatively cool, oxygen-rich water and that isn't typical of most community tanks. You're aiming for about 22-24 C/72-75 F in terms of temperature and a turnover rate of at least 8 times the volume of the tank per hour and ideally at least 10. In other words, assuming a 55 gallon tank, that would need filtration rated at 440-550 gallon/hour. Such conditions wouldn't suit most tetras, which either need warmer water or more gentle filtration. Giant danios, swordtails, and perhaps some of the barbs such as torpedo barbs would be closer to the mark in terms of temperature requirements, preference for fast-flowing water, and of course overall size.

Cheers, Neale

 

[Squidward]

Black ghost knifefish are most worm and insect larvae eaters, and while they do eat small fish, they do so opportunistically. As others have said, on many occasions they ignore smaller fish, presumably where they're well fed on foods they like. Starvation is a common problem with black ghosts, especially when they're kept alongside loaches and catfish. Under such circumstances, who can blame them for eating a few neons if that's what they need to do to stay alive?

There are other reasons to review your aquarium though. Black ghosts need relatively cool, oxygen-rich water and that isn't typical of most community tanks. You're aiming for about 22-24 C/72-75 F in terms of temperature and a turnover rate of at least 8 times the volume of the tank per hour and ideally at least 10. In other words, assuming a 55 gallon tank, that would need filtration rated at 440-550 gallon/hour. Such conditions wouldn't suit most tetras, which either need warmer water or more gentle filtration. Giant danios, swordtails, and perhaps some of the barbs such as torpedo barbs would be closer to the mark in terms of temperature requirements, preference for fast-flowing water, and of course overall size.

Cheers, Neale

Neale,

Wouldn't BGK want slightly warmer conditions coming from the Amazon?

 

[N0body Of The Goat]

I suspect this is all about the oxygen saturation levels, which will be far higher at the lower end of the scale for a BGKF at ~22C, just like other riverine fish from the American continent like Chaetostoma (so often kept in conditions which are not ideal, not enough flow and too warm temp and therefore not enough O[sub]2[/sub]).

 

[nmonks]

Nope. Corydoras, neons and black phantom tetras are further examples of South American fish that prefer cooler conditions than many suppose. Unless you've got a good reason to do otherwise, many, perhaps most South American fish are best kept at up to 25 C/77 F.

Cheers, Neale

Wouldn't BGK want slightly warmer conditions coming from the Amazon?

I suspect this is all about the oxygen saturation levels, which will be far higher at the lower end of the scale for a BGKF at ~22C, just like other riverine fish from the American continent like Chaetostoma (so often kept in conditions which are not ideal, not enough flow and too warm temp and therefore not enough O[sub]2[/sub]).

Quite right. I may be over-stressing temperature a bit here, but there is a common problem just as N0body Of The Goat says, where people keep fish so warm they can't get the oxygen they need, and there's a shortening of their lifespan. The cooler the water, the more oxygen. With Apteronotus, I'd be more worried about lack of oxygen and poor water quality than anything else. The cooler you keep them, within reason, the more oxygen and the less food they eat, so the less strain on the filter. Of course if they're too cold their immune system will pack up, and they'll get sick. But something between 22-25 C should be about right.

Cheers, Neale

 

[croggy]

o.k guys and gals got myself a new tank 75" by 12"

got it for 99p as it had no bottom

i have fitted a (temp) plastic coated steel sheet for the bottom and it seems to of sealed

just gotta spend the next two days rinsing it and hopefully when i do my water change on monday that water can go towards setting up the new tank

as to the BGKF starving i have already heard about this problem so what i do is crumble up about 5 frozen blood worm and sprinkle them into the tank and wait for him to come out then i put in my usual mix of blood worm and flake food. as most of my other fish go straight fo the flake he flies around and sucks up all of the blood worm. so i think he is very well fed ( well i hope so after all the effort that it takes


at the moment i also have a platic sheet (drilled) in the tank dividing it in two , the neons can come and go as much as they want but the BGKF is stuck in one half
so hopefully i should be o.k. for the next few weeks

on a side note will a steel sheeted bottom hurt the fish?
reason i as is i know galvanizing can harm fish and underneth the plastic coating this sheet is galvanized. i don't think it can soak threw but i was just woundering incaase anyone else on here has any knowledge

thanks for all the help