New mollys

[Characf]

So I've recently bought mollys from Maidenhead Aquatics and they said guppies and yoyo loach/black skirt are a no go.

But I've never witness aggression from the yoyo loach but the black skirt were particularly aggressive to these two new mollies I'm guessing because they look similar? Will the chasing and nipping stop? Hopefully it's a new fish thing.. also could explain why I had some dead guppies / small sword tails

 

[Wills]

Apart from the Guppies - Mollys, Yoyos and Skirt Tetras can all be nippy and in most cases its because they are not in the right numbers. For the Skirt Tetras you want them in 10+ to avoid them being aggressive to other fish, YoYos are best in groups of 5+ (but more the better) and Mollies (and most live bearers) are best in a 2:1 ratio of females to males - but more females will always help.

The other thing to mention is that the Guppies and Mollys will do better in hardwater, the Yoyos in soft to neutral and the Tetras in soft water (though Skirts are pretty hardy). But I don't think thats what Maidenhead would have been saying.

Wills

 

[Characf]

Apart from the Guppies - Mollys, Yoyos and Skirt Tetras can all be nippy and in most cases its because they are not in the right numbers. For the Skirt Tetras you want them in 10+ to avoid them being aggressive to other fish, YoYos are best in groups of 5+ (but more the better) and Mollies (and most live bearers) are best in a 2:1 ratio of females to males - but more females will always help.

The other thing to mention is that the Guppies and Mollys will do better in hardwater, the Yoyos in soft to neutral and the Tetras in soft water (though Skirts are pretty

I've got 5 black skirt, 4 yoyos, I've only got a 300L tank so didn't want crazy numbers I got advised these numbers would stop aggression. And I've just got 2 male mollies atm.

As far as water, mine is very hard, the tetras were a newbie mistake. I now know they're soft water but got advised because they're tank bred they'd be fine but I also got told yoyos would be suitable for my water aswell?

Loads of conflicting opinions in the fish community is something I've noticed very early on

 

[Essjay]

We now know the minimum number for shoaling fish like black skirts is 10 not the 6 which used to be recommended. Nippy tetras need even more than that, 15+ is the number to look at. Whoever told you that 5 is enough to stop aggression is wrong.

 

[Clivepullen]

We now know the minimum number for shoaling fish like black skirts is 10 not the 6 which used to be recommended. Nippy tetras need even more than that, 15+ is the number to look at. Whoever told you that 5 is enough to stop aggression is wrong.

I was also sold two male mollies and in the beginning all was well, but as the subordinate aged he began to challenge the alpha more and more, the moment the alpha got a little poorly - all hell broke loose to the point i had to remove the alpha to protect him. My point? It's trouble waiting to happen. Maybe you could be OK in a 300 litre tank - somebody here will know more
Essay is that the same with denisons? I've read that grey should be in groups of 5 to 6? I was planning to introduce another 3 on Wednesday bringing their number up to 5.

 

[Essjay]

Yes, denisons are also shoaling fish. More info on them here, though it does say 6 to 10 but probably written before we realised that 6 is not really enough for shoaling fish.

Sahyadria denisonii – Red-line Torpedo Barb (Barbus denisonii, Puntius denisonii) — Seriously Fish

www.seriouslyfish.com

 

[emeraldking]

Loads of conflicting opinions in the fish community is something I've noticed very early on

Unfortunately, this does go for a lot of info about fish on the internet...
To a novice aquarist, it remains vague what the exact info concerns with all the different remarks...

 

[Byron]

There is a lot of confusion in this thread over what fish you have and the tank size and water parameters. Denison barbs need a large tank, and a group close to 10 minimum. @Essjay has dealt with the tetras and loaches. I can promise you that assuming these fish are "normal" to begin with, and live healthily, these aggressive issues will appear sooner or later. We cannot change what is programmed into the DNA of each species. We must research the species' needs and provide accordingly if we car about the fishes' well being.

What is the tank size (dimensions and volume as these are separate) and just what fish species and how many are in this tank now?

 

[Characf]

Unfortunately, this does go for a lot of info about fish on the internet...
To a novice aquarist, it remains vague what the exact info concerns with all the different remarks...

Luckily I've been fortunate, they seem to get on relatively okay. Black skirt seem to be the most dominant fish but haven't seen them being too aggressive.. saying that I did have some unexplained deaths a month or so back but swordtails were equal in size so I presumed it wasn't the BST

 

[Characf]

There is a lot of confusion in this thread over what fish you have and the tank size and water parameters. Denison barbs need a large tank, and a group close to 10 minimum. @Essjay has dealt with the tetras and loaches. I can promise you that assuming these fish are "normal" to begin with, and live healthily, these aggressive issues will appear sooner or later. We cannot change what is programmed into the DNA of each species. We must research the species' needs and provide accordingly if we car about the fishes' well being.

What is the tank size (dimensions and volume as these are separate) and just what fish species and how many are in this tank now?

This isn't really relevant anymore because the aggression has stopped, was just new fish pecking order.

But as in my previous posts I have very hard water around 19, 7.5ph, 0amm 0Nit 30Nitra
Weekly water changes of 35%
Currently stocking
10 guppies (10 have died, I did have 20)
3 swordtails (2 died)
5 platys (2 died)
4 yoyo loach
5 black skirt tetra
1 bristlenose plec (never see it, I presume it's still there)
2 mollies
6 xray tetra
5 albino Buenos Aires tetra

Tank is 4x2x2 ft, around 300-350L

 

[Naughts]

Tank is 4x2x2 ft, around 300-350L

The TFF aquarium calculator gives those dimensions as 453 litres/ 120 US gallons?

 

[Wills]

19 is super hard! But I feel your pain my old house was 19, I'm now around 13 after I've moved which gives more options.

At 19 your livebearers will likely be ok, but the others may have shorter lifespans than they would in soft or neutral water. In harder water, fish found naturally in softwater can develop essentially kidney stones that will shut down their kidneys etc etc as their bodies cant process the additional elements in the water.

Your Tetras are not a terrible choice, the Black Skirts are so commercially bred it might not be too sensitive to hard water. X-Rays have a huge distribution in the wild so do start to reach coastal waters which are typically harder and Buenos Aires Tetras are quite closely related to Tetras found in harder water in Central America (though they are from South America in softer water) also an albino strain will be many generations deep in captivity so could be more prepared for some hardness, though likely not 19.

It does seem like you are losing quite a few fish so if you are open to it we can probably suggest some better options as a 120g tank you have loads of options - just a few quick ones, Central American Cichlids, Tanganyikan Synodontis Catfish and Rainbowfish would all do great in here. Yellow Panchax, a couple of Barb species come from these kind of waters. Lake Inle is an interesting hard water habitat too, Thick Lipped Gourami, Emerald Rasbora, Rummy Nose Rasbora all spring to mind so there are great options out there. Or if you ever wanted something totally different Malawi Cichlids, Peacocks or Mbuna would be great in water this hard.

Wills

 

[Characf]

19 is super hard! But I feel your pain my old house was 19, I'm now around 13 after I've moved which gives more options.

At 19 your livebearers will likely be ok, but the others may have shorter lifespans than they would in soft or neutral water. In harder water, fish found naturally in softwater can develop essentially kidney stones that will shut down their kidneys etc etc as their bodies cant process the additional elements in the water.

Your Tetras are not a terrible choice, the Black Skirts are so commercially bred it might not be too sensitive to hard water. X-Rays have a huge distribution in the wild so do start to reach coastal waters which are typically harder and Buenos Aires Tetras are quite closely related to Tetras found in harder water in Central America (though they are from South America in softer water) also an albino strain will be many generations deep in captivity so could be more prepared for some hardness, though likely not 19.

It does seem like you are losing quite a few fish so if you are open to it we can probably suggest some better options as a 120g tank you have loads of options - just a few quick ones, Central American Cichlids, Tanganyikan Synodontis Catfish and Rainbowfish would all do great in here. Yellow Panchax, a couple of Barb species come from these kind of waters. Lake Inle is an interesting hard water habitat too, Thick Lipped Gourami, Emerald Rasbora, Rummy Nose Rasbora all spring to mind so there are great options out there. Or if you ever wanted something totally different Malawi Cichlids, Peacocks or Mbuna would be great in water this hard.

Wills

Appreciate that, very interesting. I'll let this community tank run it's cause and if they're struggling or eventually die off I'll look at more suitable fish

 

[emeraldking]

So I've recently bought mollys from Maidenhead Aquatics and they said guppies and yoyo loach/black skirt are a no go.

I've got most of my mollies combined with guppies and they've been doing fine together for years.