Are My New Fish Murderers?!

[Sophie Angelfish]

I bought a new tank in September and originally bought 3 swordtails and 2 platys.
 
A couple of weeks ago I decided it was time to introduce some more fish so I bought 4 male guppies and a sucking loach. Within the last week all 3 of my swordtails and one of my platys have died.
 
I think a couple of my guppies are being aggressive as I've seen them nipping at the others so wondered if this is what's killed my original fish?
 
Before dying one of my swordtails developed a bright red head and was sort of peeling. The others just struggled along the bottom of the tank unable to really move before dying.
 
Please help!

 

[leighton_87]

What is the size of you tank?

Do you have a water testing kit? If so what are the parameters?

How often and how much water do you change?

Is there anything else new in the tank - new food? Ornaments? Wood? Rocks?

 

[phoenixgsd]

were your swordtails male or female, more than one male can lead to aggression

 

[PlumbersMerchant]

My guppies were buggers. I had one that was heavily pregnant but not quite ready to drop. woke up one morning and there was part of the pregnant guppys side missing. the other guppys were going for it and i must admit when i seperated it into a birthing tank its wound did look almost peeled around the edges. dont underestimate the power of guppies lol

 

[Sophie Angelfish]

The dead fish are 1 male swordtail, 2 female swordtails and one male platy.
 
The tank is 50 litres, no new ornaments or anything, haven't tested or changed my water recently as I'd finally got it to be ok (had it tested at the aquatics shop). Now they're picking on the one female platy I have left (as if life isn;t bad enough cos she's just lost her boyfriend!)

 

[Liam2368]

Your sucking loach could be your problem when the lights go out. They get very territorial more so when they are bigger and often suck on other fish as they like the mucus. Tank mates should be chose wisely with these fish, it is not a fish that is suitable for your tank long term.

 

[Winnar]

I agree with Liam2368, Sucking loaches are nasty little creatures. I kept one in my very first tank, 3 years ago, and It killed almost all of the other fish, save for a pleco. IMO the loach would explain for the redness (thats where it sucked on the other fish) and the peeling (a result of a lack of mucus on the fishes skin). I would return the little guy, if possible.

 

[Gilli]

The dead fish are 1 male swordtail, 2 female swordtails and one male platy.
 
The tank is 50 litres, no new ornaments or anything, haven't tested or changed my water recently as I'd finally got it to be ok (had it tested at the aquatics shop). Now they're picking on the one female platy I have left (as if life isn;t bad enough cos she's just lost her boyfriend!)

 
I assume your tank is cycled - although if you dont have a water testing kit I dont know how you knew when it was?
 
If you keep fish you really need a water quality testing kit - dont rely on periodically taking it to the fish shop for testing for 2 reasons -
 
1. the water quality can change rapidly, and
 
2. quite often the fish shop are wrong!!
 
Buy a water testing kit asap as its the first thing you test if you have a problem and without it you cant cure the problem if you dont know what it is! They seem expensive but they will last you for a year or more!