Bad Fish For Unexperienced/newbie Aquarists

[Lunar Jetman]

Thing is, any fish is a bad fish for a beginner if they're not doing things properly... But I get the point of the thread...,

 

[N0body Of The Goat]

Red Tailed Black/Albino RT/Ruby Sharks (way too nasty and sold to tanks far too small and peacefull)
Silver Dollars
Tiger Barbs (never understand why people so  stubbornly insist one wanting groups of 4 or 5, they belong in groups of 20+ or not at all imo)
Clown/YoYo/Red Tail etc etc etc Loaches
Synodontis
Blue/Gold/Three Spot Gouramis (easy species to keep and yet new fish keepers never fail to turn a peaceful fish psychotic by not understanding their needs).

 
I'm shocked that synos have made your blacklist MBOU, many common ones are hard as nails (they can be found in shocking health conditions yet survive and recover) and not all are as spiteful as nigrita/angelica. Some need more specialist conditions like Mats' and my brichardi, but others are very tolerant of a wide range of water chemistry and conditions. Others are very social like Corydoras (decora; flavitaeniata; nigriventris; congica; robertsi) and are safe around the tiniest of tankmates.
 
Have you had more than the odd issue arise through work? 

 

[Messi]

I'd say territorial fish that can 'accidently' be bred in community tanks. Mainly convict cichlids because they are one of the most aggressive tropical fish on the market and have the potential to beat up and kill 10 times as big as them to protect their fry. There are some others which are less aggressive but still not suitable for noobs such as Kribensis and Angels.

 

[MBOU]

Im not thinking of them as aggressive NOTG! I love synos

especially S. schoutendeni (spelled right i think!?) which are small and look epic as a shoal!
 
Trouble is, most common synos are unfortunately Eupterus or hybrids of said species and they may look cute at about 2cm... at closer to 20cm they are considerably less so, especially when in a 35L tank and they have eaten all the guppies and neons.
 
The problems with synos is through no fault of their own, though... same could be said for all species listed! But if you go round most shops you'll see all sump tanks have at least one poor syno in it if not a small army of the darned things...
 
Just a misunderstood species! Partly the seller, mostly the buyer.
 
EDIT: Angels is a true one!!
 
Took in three angels off a customer, barely adults... half grown maybe... 60L tank and one poor mite had no fins at all... well i lie... it has a stump of a tail and dorsal, one pectoral and one and a half ventrals...
 
Customer was all "they are fine in that size tank, been in it years!! never had a problem before now... they are all definately girls... definately, i got a mate to sex them for me...."..
 
Poor begger with no fins is now in 500L tank with rainbows and a male angel and is managing just fine and dotes on the male, the other two spawned within an hour of being on system and currently have wrigglers!
 
All girls my backside they quite clearly werent.
 
Its just typical, 11 half grown/full grown angels brought in in 3-4 weeks because people are too stupid to do some bloomin research or adapt their tank to the fish they decided to buy. Not that angels bother me, can always find homes for big angels at least!

 

[N0body Of The Goat]

Very true about hybrids and euptera/nigrita mislabelled as nigriventris (size and attitude difference). I hate how hybrids are becoming increasing common, for instance selling hybrid sp. 5 as decora, or hybrid sp. 9s as brichardi/ornatipinnis.
 
S. schoutedeni can get "golf ball" stomachs, not sure if I've seen them in the flesh to date!

 

[MBOU]

None of mine seemed that bad for getting really fat! Not to say they werent pigs though!! But they never seemed to gorge themselves like pictus cats or talking catfish do!
 
I had 6 of them, two adults, three mid sized and one tiny one. Found them in a sump at one of the MAs, St Albans i think! And they just lumped them in the 'Synos- £5 each' range... so was like... heck yeah!! £30 for 6 beauties well... would have been £30 for anyone else I got them much cheaper lol.

 

[Welshweeks]

What about otto's as they require a more mature tank?

 

[MBOU]

I dunno on that one, I personally think Otos are a lot toughr than people give them credit for!! Trouble is, the species in general has been coming into the country in poorer and poorer condition IMO and its giving them a bad rep.

 

[Welshweeks]

I understand what your saying. I think it's much better if you can source your fish from a local breeder, I was lucky enough to get 2 BN plecs locally and they are coming on lovely and I'm also waiting on a pair of electric blue rams which I'm looking forward to homing.

 

[DerpPH]

Monster Growing Fish
 
Nile perch
Mbu Pufferfish
Fahaka Pufferfish
Stingrays
Red Tailed Catfish
Pangasious Catfish
Tiger Shovel Nose Catfish
Pacu
Arrowana - black, gold, silver, jardini etc etc
Lince Catfish
Spotted Gar
Florida Gar
Sturgeon
Dorado
 
 
Large Growing Fish (12 inches +)
 
Common Plec
Sailfin Plec
Oscars
Tinfoil Barbs
Clown Loaches
Bala Sharks
Goldfish
Texas Cichlids
Veija Cichlids  (big generalization I know but fitting for here I think)
Ornate Pictus Catfish
Sun Catfish
Flag Tail Prochilodius
Some Synodontis
 
 
Fish with common misconceptions - creating issues for newbies later on
 
Goldfish - nuff said 

Siamese Fighters - dont do well in big tanks, need filters, not well kept in novelty tanks
Blue and Gold Rams - need high temperatures and low ph, most of the time. Some captive bred ones are more flexible but very hard to tell them apart...
Zebra Danios - hyperactive little fish that need the run of a big fish
Siamese Algae eaters-Needs mature tank setup
ottos-also need mature tanks
 
Very sensetive fish
 
Puffers-Sensetive to deteriorating water conditions
Discus-needs higher temp than other fish and needs frequent large water changes
 
Hybrids-very unpredictable behaviors
painted dyed or tattoed fish
painted tetras
tattoed molly
painted cory
painted loaches
 
Marine setups
 
seahorses
pipefish
pretty much ALL tangs (especially regals and powder blues!)
big angels...
dottybacks
starfish
anemones
 
 
 
keep em comming guys!

 

[TallTree01]

Tandanus catfish.
Very tough but due to massive size/ aggression really only suited to ponds/ lakes/ swimming pool sized aquariums.