All Guppies In Community Tank Are Dying

[Hobbit42]

I have a community fish tank that has been fine for awhile, I recently
bought some new fish from the pet shop, which I think introduced something into
my tank.

All of my guppies are dying, they are the only type of fish to be affected, the bettas, tetras, loaches and catfish etc are unaffected.

The guppies develop kinda transparent white patches on their bodies, their scales stick up slightly, like something is under them or they are coming loose and they die, even the ones that look healthy are dying.

It's not ich as I've dealt with that before and more than just the guppies were affected.
 
They are in about a 13 gallon tank with 9 fish to which I added 1 new guppy and 2 striped kuhli loaches.

 

[techen]

Well for starters you are overstocked. A 13 gallon is quite small. The catfish will have to go, I doubt it's having a fun time.

As for your guppies. There could be a infection that has passed off the new fish. Just not sure what it is.

 

[Lunar Jetman]

I suggest you give us a full list of all your fish and details of your water stats so we can see if we can find out what is going on in your tank. I think Techen maybe right though that you are over stocked. If this is the case your Ammonia and Nitrite levels may be above 0 which could be the issue.

 

[the_lock_man]

Could you be a bit more specific on exactly what fish you've got? Saying "catfish" is too general, likewise "tetra". Some catfish species are huge, some are teensyweensy.
 
And I'm a tad concerned about "bettas" too - given that the majority of bettas in people's tanks are male betta splendens, that will fight each other to death.

 

[Hobbit42]

 only 1 male and 2 females betta, 2 black skirt tetra, 1 glass catfish, 2 striped kuhli loach, my last surviving guppy and my mystery golden snail and a bunch of snail babies are whats left in the tank
 
Noy sure about the water stats, they were fine but i let a friend borrow my testing kit and havn't seen it since, so i'll have to pick one up soon
 
tanks get about a 30-40% water change once a week with a gravel clean, temps usually 24-25 c, the tank is also fully planted to help with amonia buildup

 

[phoenixgsd]

as already said your very overstocked and quite badly stocked too, glass cats are very sensitive and need to be in larger groups prefrably in a mature tank, khulis also need to be in groups of 6 plus, male and female bettas should idealy not be housed  together especially in such a tiny tank,  guppies and male bettas also dont mix, betta mistakes the flowing fins on a guppy as another betta and the injuries that killed your guppies could have been caused by the bettas agression, i would seriously consider  rehoming some, and yes, deffinately get a test kit (liquid based) ASAP

 

[This Old Spouse]

+1

 

[Hobbit42]

I thought it had to do with temperament, the bettas were in a tank together before, first divided then together,  and they were never aggressive towards each other, it's why I decided to place them in a community tank.
I've had a few of them before, Some were pretty chill, some just wanted to kill everything.
 
As far as i know the bettas were non aggressive towards the guppies, I did and still do monitor the fish for aggression in tank as i know this could happen.  The guppies themselves did not have bright colors or long flowing tails, I choose them specifically for that purpose, as I was also advised that those could cause bettas to be aggressive.
 
As i said white filmy patches that only appeared after introduction of new fish.
 
 also I thought the general rule was 1 inch of fish per gallon
 
Guess it doesn't matter now as all the guppies are dead. All the other fish show no signs of stress or infection. I'll set up my new tank and move a few.

 

[AshP1986]

The bullying could be occurring at night, if it was the betta causing the problems. The patches, if they are due to fish fighting, could have only occurred after the introduction of new fish because the betta felt crowded and was defending his territory. Male bettas should be kept alone. period. end of story. 
 
It is vital that you know what your levels are, just because the guppies are all gone (which leads me to think it was the betta), doesnt mean your tank is good to go. You could still have a water quality issue. If you can't afford a test kit right away, as they run about 25 bucks, then go to your lfs and have them test your water. Many do it for free. Just make sure they use liquid and not strips.... 
 
The one inch per 1 gallon is the general rule, but that is for the adult size of the fish. Also, like some have stated, some of the fish you have prefer to live in groups and will pick on other tank mates if they are not in the correct group size. 

 

[Lunar Jetman]

If you can't afford a test kit right away, as they run about 25 bucks, then go to your lfs and have them test your water. Many do it for free. Just make sure they use liquid and not strips....  

I'd suggest a water change fairly quickly and regularly too. It won't hurt the fish and can only benefit them, especially as you're overstocked and you have no idea on the conditions in your tank.

 

[the_lock_man]

Male bettas should be kept alone. period. end of story. 
 
 

 
Disagree with this. IME, temperaments of male fighters vary tremendously, more so than any other fish I've ever kept. Some are the devil-incarnate, and can only be kept on their own. Others are as soppy as a sack of spaniels, and could be kept with pretty much anything.
 
I am amazed, though, that the OP has successfully kept a male and 2 females in the same tank. They are betta splendens aren't they?