gonzo127

ok so my main tank has really got me confused ok so it is only a 60L tank (~16 US gal) but just recently over the past 3 weeks we have had all of our fish die which was
6 neon tetra's (4-5 months)
1 Guppie (have about 2 years)
2 Platies (1 had about 2 years other about 1.5 years)

i use the API liquid master kit and have checked the water after every death and my readings have never been above
ammonia = 0
nitrite = 0
nitrate = 20 (usually around 10)

my lasy addition to the tank was the tetra's about 4-5 months ago so i dont think it is a 'brought in' desease, and i have checked each one for any un-usual marking or visable issues once i have removed them and cant spot anything

therefore i am wondering if anyone can suggest something which might have caused this sudden mass death in my tank,

if it would help i have been informed by my wife that i have to remove the last platie from the tank tonight when i get home from work (who must have passed away last night or this morning) so i could take a picture or two of her if people wanted to double check her for signs of disease (however i know most people probably wouldnt want to see a picture of a dead fish on these forums but i am sure we could work around that somehow if it would help)

i am going to try and keep my tank cycled (couple of bits of prawn in the bottom of the tank this evening) so that if i can work out what has caused the problem i can try and fix it and get in some new fish as soon as possible as i miss them, but i dont want to risk it untill i am a bit more sure about whats happened, this is unless people think it would be better to let the tank become uncycled incase there is a disease in the tank and that might kill it.

please any suggestions would be helpful at this point as i dont want to put any other fishes lives at risk untill i know what has happened

Lucy

I'm sorry about the death of your fish.
Were they showing any sings of illness?
A couple thoughts to throw out to you.....when you put your hands in the tank, were they free of soap, lotion etc?
Has anything been sprayed (air freshener, bug spray etc) near the tank?

Are there any fish left in the tank?

gonzo127

Well each fish has done something different before they have died so i will list what i noticed of each of them and the order of the deaths

One Platie seemed fine the night before had a couple of 'mad moments' where she was all over the tank and just didnt stop zooming about but this wasnt too much out of the ordinary for her
a couple of the Neons went to the other side of the tank to the others and just rested on the bottom, and was dead the next morning
the guppie had a couple of bits of tail fin missing thought this was down to the remaining 4 neons since there school had dropped too low so was going to buy some more at the next possible chance however didnt get a chance since she was dead 2 days later, however we never caught the neons attacking her
remainder of neons have died one after the other no major differences in normal behavour the day before
last platie has died last night / this morning and she was rubbing against one the the pots in the tank yesterday

as far as hands go i dont use lotion and always make sure i have throughly rinsed and dried my hands before i do anything to them

as for sprayign things, the closest place some spays anything is about 2m (7-8 foot) away and the tank does have a full hood

Lucy

Hmmm.......any new decor that could have drastically changed the pH?
Maybe someone else will have some ideas.

harpua2002

Maybe there was a contaminant in your tap water?

gonzo127

nope no new decor, this is why i am completely confused, everything has been stable for about 4 months and suddenly within 3 weeks 9 deaths!

hmm contaminated water i dont beleive so as i use a water conditioner and my second tank which also has a school of Neons in it hasnt had any deaths and i have used the same tap and equipment for water changes in both tanks over the last 3 weeks

gonzo127

well some good news, the platie which my wife told me was dead was actually still alive although very still and shy at the back of the tank but still alive

aquarist48

Hello. So sorry to hear about your fish loss. Are you doing regular water changes and vacuuming?