Dead Guppies

[S30TT]

Hi all,

i have a community tank with , a couple of angels, a pleco, red tailed black shark, a few black widow tetras, neons, a few platties/swordtails and 2 clown loach.
A few weeks ago i purchased about half a dozen guppies(female) then the following week about 7-8 guppies(few female few male)
now, ALL of those guppies are dead, all died within two weeks of having them. My tank is well established and i havn't aded any new fish for quite a while, all the other fish i have have been there for ages.

Any ideas as to ahy these guppies didnt survive?
I assume my water is ok as all my other fish are absolutely fine.
could my water conditions not be suitale for guppies?
i did notice that from the day i got the guppies til the all died(one by one) tat they were permanenlty swimming very near to the surface of tank

 

[WILDER]

Take a sample of your water to the lfs and tell them to right the readings down for you.
How many gallons or litres is the tank.

Were they gasping at the top of the tank as that can mean a number of things, bad water quality to parasites.

Looked at your profile is that a 20 gal tank as if so its overstocked.
Red tailed shark need 40 gals.
Angels nothing less than 30 gals.
Clown loaches have to be kept in groups and need tanks even when small nothing less than 50 gals.

 

[S30TT]

ahhh, so it sounds like my tank is too small/overstocked

thing is, the fish that are in there have been happy for a year now, i had to down size from a 4 foot tank when i moved back in with parents.

i have not tried adding any fish for ages but when i got the guppies the above happened.

Maybe i should just leave the tank as it is, as it appears to be ok. i have an external filter which was more than adequate for my 4ft tank so i would imagine this will help with my little 2 footer??

All my existing fish seem more than happy.

Will get water tested anyway.

cheers for help