Why are all my guppies dying?

[paulc]

My tank has been established for nearly 3 months (after cycling). We had 3 black widows, 3 black tuxedo platies and 5 guppies.

Approx 20 days ago we introduced 5 more guppies (bag in the water, lights out etc). After a few days one guppy died and we noticed that most of the guppies had damaged tail fins, which we guessed was aggression from the other fish. A couple of days later a couple of the new guppies developed ich which I treated with medication and it went away, but in the last 10 days we have lost all the guppies except for two. Before dying the guppies seem to darken slightly in colour. The other fish seem unaffected, is there a guppy disease I’m not aware of?

I’ve been doing fortnightly water changes of 25% and vacuuming the gravel at the same time. Nothing has been added to the tank. I feed them everyday with flakes and the odd bloodworm once a week

Ammonia: 0
Nitrites: 0
Nitrates: <15
Temp: 78F
Tank size: 92 litres

Any help would be much appreciated
Thanks
Paul

 

[docrak]

What was your ratio of male to female?

Did you observe any aggression?

Could have been something they brought from the store, I can't see any other issue that would cause this. There is no specific live breeder disease I can think of.

 

[paulc]

What was your ratio of male to female?

Not sure, is this important for future stocking?

Did you observe any aggression?

None at all, it must have happened overnight when the lights were off. Since then its been fine

Could have been something they brought from the store, I can't see any other issue that would cause this. There is no specific live breeder disease I can think of.

Thats the conclusion I'm coming too, but its very odd none of the other fish have been affected

 

[StyleUK]

Thats strange, my guppys and been doing the same thing for the last 3months, the just darken in colour and die a few days later. I've never found out what it is, but if anyone could help it would be nice.

Guppys only leave for a year anyway, so maybe you just had some old guppys, then again if you braught them from an LFS then i doubt they would have been that old.

All my guppys are male, none of them fight at all, they just like to school with themselves in the reflection of the glass lol.

Male guppys are normaly quite bright and big, they have bigger anal fins aswell and a bigger tale in general, quite bushy. Females are dull and boring, don't get me wrong they're still great but just not as colourful and smaller.

 

[docrak]

What was your ratio of male to female?

Not sure, is this important for future stocking?

Ratio is super important with live breeders. An all male or female tank is fine but mix the two and you could have a huge problem. The males can be very aggressive towards each other over breeding rights. I've lost several males do to this type of agrresion. Some people suggest two to three females per male to reduce aggression. This doesn't always help sometimes a male is going to be aggressive no matter what. I would suggest no more than 2 to 3 males per tank if you want to breed which means you would need 6 to 9 females. Better like guppies if your going to keep that may females.