Swordtail disaster - whats going on?

I waited 3 months for a 20g tank to cycle, planted it well, then started with a few zebra danios then added a few more...kept watching water parameters to ensure good. Then for my daughter who wanted to breed livebearers i got 2 male and 3 female swords from a reliable LFS.
Fish all seemed happy - eating fine, I checked and am still checking water parameters every other day...and one female died the first night...now one of the males just died. All other fish are good and eating and water parameters are good (7.0 ph, zero ammo, zero nitrites, nitrates <5ppm). What could be going on? I have much more challenging fish in other tanks and never had anything like this happened. thank you!

 

This isn't much information, any signs of illness? Ich/white disease, columaris, finrot, any signs of aggression from the danios or other swordtails. Maybe attach a photo and fill out the emergency template.

 

IMO 20g is too small for swords.
My guess is the alphamale is killing the others .
They can be a tough not so little fish.
I had a jet black male that would kill every male if there were less then 10 others in 75g!

 

IMO 2 males and 3 females isn't a good ratio, when I had 2 to 4 the subdominant male was regularly chased by the dom if he came out into the open, in a tank twice the size. No prizes for guessing which one died. The dom might not have killed him in a fight to the death, but the stress probably did. My LFS don't take fish from customers and I didn't have space for another tank, otherwise I would have separated them.
Did the first death occur on the night you introduced them to the tank? How long between the deaths?

 

thanks for all the help. my LFS told me that 2 males and 4 fems in a 20g was plenty of room. That's what i got. one female died the first night. now this morning the second male is dead. (i.e. both males died within 12 hours of each other 5 days after I got them). It must be stress and i got very bad advice from the LFS. Now I have 3 females (only) and they look pretty stressed. They all looked great - no disease - this must be stress and i made a terrible mistake.
any suggestions on what to do now?

 

The first thing to do is not blame yourself or feel bad about it. The vast majority on here have made mistakes. Secondly, if you have only had the fish for 5 days complete the emergency template. I may be wrong but 5 days seems to be quite quick if it is stress from being chased around. A pic of the tank may help too.

 

Yea in a 20 (I presume it is a 20 high and not a 20 long); i'd go with something smaller like guppies or endlers. I had 3 swordtails in my 29 and they sort of dominated the tank. The other thing is that you didn't mention your water hardness/softness (gh); all live breeders like hardish water. Finally (not life or death) but all live bearers love plenty of plant matter to munch on - this includes live plants and algae.

 

my LFS told me that 2 males and 4 fems in a 20g was plenty of room.

When they're still not fullgrown, this could work. But fullgrown swordtails need sufficient open swimming space. The way they're build already shows that. So, that's why members overhere will advice a larger tank.

all live breeders like hardish water.

Correction: A lot of livebearers like hard water. For there are livebearer species that are better off in softer water. The hard water issue is more of a generalization than a fact when mentioning "all livebearers".

I've got some dominant males in my swordtail colonies as well but they're not killing other males or females. But they do compete with another from time to time. Just to see which one is the "man" amongst those males. But my colonies are probably bigger than most of yours. This makes fighting become less till even none.

 

thanks v much. All helpful - i will re-check my gH tonight and report back.

 

I've got some dominant males in my swordtail colonies as well but they're not killing other males or females. But they do compete with another from time to time. Just to see which one is the "man" amongst those males. But my colonies are probably bigger than most of yours. This makes fighting become less till even none.

What size tank ? I suspect crowding will change fish behavior...

 

Thanks. 20g. Question will be now that i have 3 females and no males, should i get another male or return the fish to the lfs.

 

Thanks. 20g. Question will be now that i have 3 females and no males, should i get another male or return the fish to the lfs.

I was asking emerald over curiosity; i would return the 3 females to the store and try something smaller like guppies or endlers unless you dislike them. Guppies are live bearers and will breed regularly - you could try 2 males and 3 females - folks recommend higher number of females over males since males will pester females but i wouldn't be too concern.

 

What size tank ? I suspect crowding will change fish behavior...

30g Tanks. I breed multiple wild strains of swordtails.
Yes, the behavior does change when crowded for sure...

 

thanks v much. this is a 20g. here is a photo - as you can see, 3 females left (and there are also 5 small zebra danios in there. water parameters are good. question is whether i can add one male to try breeding (per above the two males in there killed each other the same day), or whether i am already overstocked.

 

thanks v much. this is a 20g. here is a photo - as you can see, 3 females left (and there are also 5 small zebra danios in there. water parameters are good. question is whether i can add one male to try breeding (per above the two males in there killed each other the same day), or whether i am already overstocked.

The issue isn't being over stocked which tends to refer to water quality. The issue is that adult swordtails are fairly large and need a reasonable amount of room for swimming and a 20 high is a fairly small tank (left to right). Having said that i'm not sure if the type of swordtails you have obtain the same size as the 'normal' ones as i've always avoided the 'fancy' species so maybe get a 2nd opinion.

 

thanks - lyretails dont get much above 2" so i thought they would be ok..but it is a 20g high, so i think they are a bit tight on swimming space. i got bad advice from the LFS... ugh.

 

Hard to say from picture but you may still have a male!
Lyretails grow the same size as most other Xips [common swords] 4-6 inches.

 

lyretails dont get much above 2"

Well, if they have the space, they can outgrow 2 inches without a problem.

 

Thanks everyone. I have a fairly well-stocked 75g (i.e not too much more room as I don't like to overstock). Has a two 3-spot gouramis, a few dwarf SA cichlids, and a few schools (5-7 each) of tetras (buenos aires, black skirt, black neon, and glowlight.
I agree that the 20g high is looking too small for those 3 swords i have left. Any views on whether to move them to the 75g (I could move some of the tetras to the 20g). thanks!

 

I would ask what species of SA cichilds are in the 75; as some are more aggressive than others; some larger other smaller and while most tend to hang near the bottom a few will spend time in mid level and i suppose there might even be a species that will go higher.

 

thanks - I have 4 rams in there - GBR, etc. all small.

 

In terms of aggression they should be fine but the rams really prefer water 82-84 which is a bit on the warm side for the swordtails.

 

good point thank you!