White Spot Medicine Killing Fish

[Darkfung]

a week ago I discovered one of my neons had white spot - I bought the medicine and dutifully put in 8ml on day 1,2 & 3 as prescribed - keeping the lights off (recommended by my shop owner) - on day 4 I find I've wiped out all my neons (8) and my harlequins (6) are emaciated and have ragged fins .... 2 have now died as well ....... the tank is 116 litres - any ideas what's happened here? I've got to put more medicine in on day 6 (tommorow) and don't want to risk it !
I've kept fish for 20 years and this is a relatively new tank (a month) with new fish.

 

[minxfishy]

Can you tell us the tank size, what fish and how many of each and the tank water stats for ammonia, nitrIte, nitrAte and ph.

Did you use any mature media from another tank to cycle the tank or are you cycling the tank with the fish in.

 

[WILDER]

Need some info on size of tank in gallons or litres.
How many fish and which type.
Water stats in ammonia, nitrite, nitrate, and ph.

Did you increase aeration with the high temp and med.
Have the fish lost weight due to not eating.
You are only meant to half dose with neon tetra's, as they don't tolerate parasite meds towell.

 

[Darkfung]

Need some info on size of tank in gallons or litres.
How many fish and which type.
Water stats in ammonia, nitrite, nitrate, and ph.

Did you increase aeration with the high temp and med.
Have the fish lost weight due to not eating.
You are only meant to half dose with neon tetra's, as they don't tolerate parasite meds towell.

Guys,
I've got some of that info. -
25 gallon tank - temp. was kept at usual 24^c (no instructions to raise this on medicine) filter was left running during the day but off at night ...
fish are 2x rainbowfish, 2xmollies, 2xswordfish, 4xguppies, 4xblind cave fish, 2xpeppered cats, 2xglass shrimp, 5 harlequins (2 now dead), 8xneons (all dead)
before treatment these were all the healthiest liveliest fish I'd kept !! (apart from my one neon who got white spot!!)
now the treatment's complete the remaining fish are all lively and healthy again apart from the 3xharlequins who are listless & thin but seem to be getting healthier ...
Chemical composition I can confirm when i get home.

 

[minxfishy]

Why would you leave the filter off at night? Filters need to be on 24hrs a day or they lose beneficial bacteria fairly quickly.

 

[WILDER]

Why did you turn the filter off at night as you can destroy benefical bacteria in the filter and also there wouldn't of been enough aeration with the high temp and med.
Also you raise temp to 30 with whitespot to speed up the life cycle of the parasite.

 

[Darkfung]

Why did you turn the filter off at night as you can destroy benefical bacteria in the filter and also there wouldn't of been enough aeration with the high temp and med.
Also you raise temp to 30 with whitespot to speed up the life cycle of the parasite.

I turn the filter off at night so that my partner can get to sleep - my tank is in my bedroom !

 

[WILDER]

If you didn't have an airstone running that would explain the deaths.