Orange Spots?

HI everyone
I woke up this morning to a bit of a disaster, 4 of my white cloud mountain minnows are dead,
I have a 70 Litre Tropical aquarium which had 2 gouramis and 5 WCMM's, Last night I noticed one of them had orange spots on its body which I hadn't Seen Before but thought nothing of it, I woke up this morning and four of them are dead, the gouramis seem fine but the last remaining minnow now has the orange spots, Does it sound as though the spots could be the problem, i Havnt noticed anything else different about them but one had slightly raised fins i think, not sure wether this could have been because its been dead for 12 hours,

A few days ago I changed around the whole tank, my heater was broken and the water was freezing cold so i bought a new one,
I also bought new sand for the bottom,

I've put in the new sand and the heater, is it possible the tank warmed up to fast and caused the fish stress? could it be the sand? is it some disease?

not that it will probably make much difference now as they are nearly all dead, but any suggestions as to what it could be?

Thanks, Ashley

..dunno is the quick answer.

Could be some kind of chemical burn if the sand or new heater wern't washed off well enough. Either that or it could be marks where the gouramis have "kissed" the mountain minnows, have they been fighting?

By the way - your hands look very dry in that photo. Its best to make sure you wash any salt off your hands (not with soap) and then rinse them with tank water if you're gonna be handling any fish. - see how its tail has started to dry out in the photo.

oh.. and update please when you can.

saz326 said:

By the way - your hands look very dry in that photo. Its best to make sure you wash any salt off your hands (not with soap) and then rinse them with tank water if you're gonna be handling any fish. - see how its tail has started to dry out in the photo.

Click to expand...

My Hand looks dry cause its zoomed in so close, and the fish are dead silly,

the last of the minnows has died now, He was swimming fine about an hour ago, now floating at the top.

I did think about whether the gouramis were sucking them or something But they have been living together for a long time, about 6 months, and haven't had one of them have these marks, and it would be strange that it would happen to them all in the space of less than 24 hours

I don't think it would be chemicals from the sand as it was produced for aquarium substrate and had no instructions to tell you to rinse first, thanks for the suggestions tho

Water stats in ammonia, nitrite, nitrate, and ph.
Did you steralise the sand before adding it to the tank.
Did you raise temp up gradually.

Any signs of darting, erratic swimming, flicking and rubbing, excess mucas, laboured breathing or gasping.
Any signs of looking pale or darker in colour, being listless and lethagic.

i'd say ammonia poisining?
test results please!

Betta_246

how high did you raise the temp in the tank and how quickly
they dont do well at higher temps - 26 max and will shorten their life

they do better and are actually meant to be in temps 7-21 degrees

check your nitrites , ammonia , nitrates and post results hun please