all fish died within 8 hours ???

[Fin-tastic Aq]

ok let me try this again i lost internet connection 2 times

my friend had a 75 gallon tank installed in there house 8 months ago
they strated out with a handfull of damsels and then bought a flame angel and a butterfly fish out of the blue they kicked off after the butterfly was put into the tank ( did not quarintine )

after 1 month with no fish in the tank she had called me to take a look at what was going on
i looked at the parameters

ph 8.3
ammonia 0.0
nitrite 0.0
nitrate 0.5
calcium 3oo ppm

everything looked good to me

Big Mistake
I put 6 1 inch to 1 1/2 damsels into the tank and 8 hours later they were all dead
i acclimated them slowly using a smaller tank and a drip line from the aquarium

now i was told later that she had some work done in her house drywall, paint ...etc
that the tank was covered but ??????
do you think im looking at a complete water change
or maybe another tank and argonite exchange
im at a total loss and got involved in a serious problem here
i have never had anything like this happen in the 5 tanks in my own home

thank you for any help

[Fin-tastic Aq]

PS
will a parasite live for a month with no host if it was the new fish (flame angel and butterfly)
that polluted the water
also fish only tank

it was after the new fish were put in that all the fish died
then again when i stupidly put the 6 damsel in there not knowing the water was fatal to them

Originally Posted by Fin-tastic Aq

my friend had a 75 gallon tank installed in there house 8 months ago
they strated out with a handfull of damsels and then bought a flame angel and a butterfly fish out of the blue they kicked off after the butterfly was put into the tank ( did not quarintine )

Most likely the addition of the last two unquarantined fish brought a parasite with them. In these circumstances, the tank must be left fallow for a minimum of 4-5 weeks to allow the parasite do die off naturally. These types of parasites cannot survive without a fish host and the problem will solve itself without the fish.

Depending on how quickly the fish where lost, I would suspect oodinium as most butterflies are prone to.

How long after the main losses where the 6 damsels added?

now i was told later that she had some work done in her house drywall, paint ...etc
that the tank was covered but ??????

Covering the tank is by no means always a sure bet. It is possible a contaminant has entered the system in which case a large water change and the addition of a high grade carbon will help remove the impurity if present.

Cheers
Steve

[Fin-tastic Aq]

it was a 5 week shift between fish in other words the 2nd batch died 5 weeks after 1st batch and this was within 8 hours after they were put in the water.

as far as covering the tank
the sump was still open the elements
fumes dust .etc........
so that is still a possable cause