Will my Angelfish kill the others?

[matthayden]

Hi,
Ive got a 165 litre tank, currently housing all young fish. I have 2 angelfish, both too small/young to tell the gender, 3 mollies (1 male and 2 females), a clown loach and a small bristlenose catfish.
Ive read that if the angelfish are both males, 1 will kill the other, if they are both females they will lay eggs but they wont be fertilised, and if they are male and female they will have fertilised eggs.
During this process the angelfish become aggressive, will they kill all the other fish in my tank or will they just become protective over one section?

 

[Liz L]

Hi Matt,
I have a mated angelfish pair and they are very aggressive to other fish. At first they were in my 55 gallon tank. But once they started mating they did nip at other fish. Although they did not kill them. They were very aggressive and now I keep the couple in a separate tank.
I had 2 females and 1 male. But once the pair bonded the left out female angel would attack the other female angel. Before the pair bonded, all 3 thrived in the same tank.
I have 10 angelfish between 5 snd 10 weeks old. Right now they all get along. But I will eventually have to separate all of them.
Angelfish need a minimum of a 20 gallon tank for 2 and they can get up to 6 inches or larger.
The mollies will probably go after the eggs, and the angelfish will become aggressive. But you still have some time before they start mating. Also not every male bonds with a female right away. They say it can be a picky process. So it might not happen in your tank. You have to see if the mating behavior starts.
Liz

 

[matthayden]

Would anyone else be able to help me?
The main questions I need answered are:
1. If they pair will they kill the other fish?
2. If they are two females will they kill the other fish?
3. If they will attack the other fish no matter what, if I sell one and have just one angelfish, will they attack other fish still?
Thanks

 

[Colin_T]

no, no, no, no, no, no, no, no and no.

Angelfish are cichlids and all cichlids are territorial to some degree, especially when breeding and defending their eggs and young. However, Angelfish are quite peaceful for a cichlid and are unlikely to kill other fish in the tank.

If you had a group of Angelfish in the tank, they would form pairs consisting of 1 male and 1 female. The first pr to form would become a dominant pr and they would bully and chase the other fish away from their territory. But they would not go out of their way to kill the other fish unless they were in a tiny tank and the other fish had nowhere else to go except the dominant pair's territory. Then there would be fights but your tank is big enough so that shouldn't happen.

If you end up with 2 males they might form a pr and hang out together like mates do but they won't attack things.

If you end up with 2 females they might pr off and lay eggs and guard the eggs & young (assuming they don't eat the eggs themself), and they will chase other fish away from their eggs, but they won't kill the fish in your tank.

If you want a breeding pair of Angelfish, get a group of 8-10 young fish and grow them up together in the same tank. As they mature and pr off, you move the prs into different tanks so they can have their own territory.

--------------------------
On a side note, you have fish in you tank that come from different environments with the Angelfish, clown loach & bristlenose coming from soft acid water and the mollies that come from hard alkaline (and sometimes brackish/ salty) water. Depending on how hard your water is and what the pH of your water is will determine if the fish will live well.

Can you get your water tested for general hardness (GH) and pH and post the results here?

If your water has a GH less than 250ppm the mollies will probably suffer. And if the pH is less than 7.0 the mollies will suffer.

--------------------------
In addition to the above, clown loaches prefer to be in groups of 6 or more but you need a bigger tank if you plan on keeping that many when mature. If you get a couple more small clown loaches and have 3 or 4 of them, they would be happier.

Livebearers like mollies, should have at least 4 females per male and preferably 6 or more females per male. This reduces the stress on the females caused by the males constantly trying to breed with them. However, depending on how hard the water is, will determine on if you should get more mollies. If the water is soft and acid avoid livebearers.

 

[matthayden]

no, no, no, no, no, no, no, no and no.

Angelfish are cichlids and all cichlids are territorial to some degree, especially when breeding and defending their eggs and young. However, Angelfish are quite peaceful for a cichlid and are unlikely to kill other fish in the tank.

If you had a group of Angelfish in the tank, they would form pairs consisting of 1 male and 1 female. The first pr to form would become a dominant pr and they would bully and chase the other fish away from their territory. But they would not go out of their way to kill the other fish unless they were in a tiny tank and the other fish had nowhere else to go except the dominant pair's territory. Then there would be fights but your tank is big enough so that shouldn't happen.

If you end up with 2 males they might form a pr and hang out together like mates do but they won't attack things.

If you end up with 2 females they might pr off and lay eggs and guard the eggs & young (assuming they don't eat the eggs themself), and they will chase other fish away from their eggs, but they won't kill the fish in your tank.

If you want a breeding pair of Angelfish, get a group of 8-10 young fish and grow them up together in the same tank. As they mature and pr off, you move the prs into different tanks so they can have their own territory.

--------------------------
On a side note, you have fish in you tank that come from different environments with the Angelfish, clown loach & bristlenose coming from soft acid water and the mollies that come from hard alkaline (and sometimes brackish/ salty) water. Depending on how hard your water is and what the pH of your water is will determine if the fish will live well.

Can you get your water tested for general hardness (GH) and pH and post the results here?

If your water has a GH less than 250ppm the mollies will probably suffer. And if the pH is less than 7.0 the mollies will suffer.

--------------------------
In addition to the above, clown loaches prefer to be in groups of 6 or more but you need a bigger tank if you plan on keeping that many when mature. If you get a couple more small clown loaches and have 3 or 4 of them, they would be happier.

Livebearers like mollies, should have at least 4 females per male and preferably 6 or more females per male. This reduces the stress on the females caused by the males constantly trying to breed with them. However, depending on how hard the water is, will determine on if you should get more mollies. If the water is soft and acid avoid livebearers.

Thankyou so much for such an in depth answer. The hardness of the water supply in my area is meant to be 150mg/l I believe and at the moment the pH in the tank is at about 7.3 but was planning on lowering it to 7.0. Ive read and been told that mollies are quite tough fish and adapt to survive in most conditions, and would go well with the angels or other fish. If the mollies are going to suffer, what other type of fish do you suggest would go well?

 

[Essjay]

Mollies are not tough fish, I'm afraid. They will become sick if kept in water below 250 ppm, as Colin said. You need to rehome the mollies.
I would also rehome the clown loach as they can grow very large. It is not a good idea to keep fish that you know will outgrow the tank, and they do need to be in a group.

Please do not lower the pH. Fish can cope with a pH outside their range better than they can cope with a hardness outside their range. I can keep soft water fish in my water which has 90 ppm hardness but pH 7.6.
The trouble with altering the pH is that it means adding chemicals to a tank, something we should not do unless necessary, and the products sold to change the pH usually result in a yoyoing pH which is a lot worse for fish than a steady pH a bit higher than their given range.

 

[matthayden]

Mollies are not tough fish, I'm afraid. They will become sick if kept in water below 250 ppm, as Colin said. You need to rehome the mollies.
I would also rehome the clown loach as they can grow very large. It is not a good idea to keep fish that you know will outgrow the tank, and they do need to be in a group.

Please do not lower the pH. Fish can cope with a pH outside their range better than they can cope with a hardness outside their range. I can keep soft water fish in my water which has 90 ppm hardness but pH 7.6.
The trouble with altering the pH is that it means adding chemicals to a tank, something we should not do unless necessary, and the products sold to change the pH usually result in a yoyoing pH which is a lot worse for fish than a steady pH a bit higher than their given range.

Is there a way to raise the hardness and should I do that?

 

[Essjay]

The problem is that you have both hard water fish (mollies) and soft water fish (everything else). You cannot keep both sets of fish happy; the choice is harden the water and keep mollies plus other hard water fish or leave the water as it is and keep soft water fish but no mollies. If you hardened the water for the mollies you'd have to rehome all your other other fish and replace them with more hard water fish.

The best site for fish research is http://www.seriouslyfish.com/knowledge-base/ If you look up your fish on there, you'll see that the angels, clown loaches and bristlenose like the same hardness, but mollies hardness range does not overlap with theirs. (Some of the profiles on Seriously Fish give the hardness range in dH; your 150 mg/l, which is the same as ppm, converts to 8.4 dH) And the profile on clown loach gives the minimum tank size for this species.

 

[matthayden]

The problem is that you have both hard water fish (mollies) and soft water fish (everything else). You cannot keep both sets of fish happy; the choice is harden the water and keep mollies plus other hard water fish or leave the water as it is and keep soft water fish but no mollies. If you hardened the water for the mollies you'd have to rehome all your other other fish and replace them with more hard water fish.

The best site for fish research is http://www.seriouslyfish.com/knowledge-base/ If you look up your fish on there, you'll see that the angels, clown loaches and bristlenose like the same hardness, but mollies hardness range does not overlap with theirs. (Some of the profiles on Seriously Fish give the hardness range in dH; your 150 mg/l, which is the same as ppm, converts to 8.4 dH) And the profile on clown loach gives the minimum tank size for this species.

No worries, I will relocate the mollies, any suggestions for fish to replace the mollies?

 

[Colin_T]

rainbowfish, see following link.
http://rainbowfish.angfaqld.org.au/Melano.htm

Most species of rainbowfish do best in hard alkaline water but they also do well in softer water as long as the pH is above 7.0. So don't change your pH.

 

[Essjay]

A lot of rainbowfish are too big for 165 litres, the smaller species would be OK. And the dwarf rainbowfish, Melanotaenia praecox, prefers softish water to hard water so is perfect for your hardness.

 

[matthayden]

Any other suggestions?

 

[Colin_T]

ruby barbs
filament/ cocks comb barbs
congo, yellowtail congo or African longfin tetras
black or red phantom tetras
smaller species of rainbowfish could include: Melanotaenia maccullochi, sexlineata, praecox, pygmaea, nigrans, exquisita, duboulayi, Rhadinocentrus ornatus, Pseudomugil signifier (bigger inland varieties not smaller coastal ones).

 

[Essjay]

To be honest, there are just so many fish that would be suitable it would take all day to give a list. Fish from south America, Asia, and rivers in Africa.

Fish to avoid - other cichlids as the angels would take exception to them; small torpedo shaped fish as the angels would try to eat them; fish that are known fin nippers as they would nip the angels' fins; fish that dash around the tank at full speed as that would unsettle the angels. Apart from those exceptions, any fish that is suitable for a 165 litre tank and the hardness of your tap water.

The simplest thing is to take a tour round your local shops and make a note of the fish that catch your eye. DO NOT be persuaded into buying anything. When you get home, look up the fish on the list on Seriously Fish. See if they are OK in your size tank; see if your hardness sits in the middle of their preferred ranges (yours is 150 ppm or 8.4 dH); read up the other information to see if they are sedate or fast swimming fish. Then post the shortlist on here.

 

[Byron]

The tank size must be kept in mind, as some of the suggestions for fish in earlier posts will just not work here. And with angelfish, even moreso. I won't detail now but move on to other issues that need resolving.

Re-home the mollies (re-home means remove them from this tank, then give them to another aquarist or the store, sell them, set up a special molly tank with hard water, or euthanize them). They will not be healthy in soft water and only becomes severely stressed, diseased and die slowly.

Re-home the clown loach. This tank is not even remotely large enough for a group of five clown loaches; they attain 8 inches fairly rapidly, then grow to 12 inches or so. They need an 8-foot tank. A single clown loach will be highly stressed, as it needs companions. Loaches are highly social fish, and this is programmed into their DNA.

On the two angelfish, it is impossible to say what they will do. All we can assume is that an angelfish will behave "normally" for the species. Two angelfish is never a good idea in this small a tank unless they are a male/female pair that have clearly bonded. Beyond that, they may kill one another (or one of them will), they may attack other fish, they may not...they are a territorial and somewhat aggressive species.