why are my guppies dieing?

Question

on friday i cleaned the tank of the fish, i changed the water and dechlorinated it, then i cleaned the rocks to remove fecal matter.

however saturday morning 2 guppies died
sunday morning another 2 died
monday night i witnessed 1 die!!!
tuesday 2 died
no more guppies to die

but the other fish are alive!
4 orange fish and 2 neon tetras!

the one i witnessed die seemed to be falling down into the bottom of the tank, although it wanted to stay up. it even used a plant to keep itself up. all of a sudden it sank to the bottom of the tank. i tapped the glass it moved and a few seconds later started to fall again..until i thought it was really dead. i got it out using a net and it moved! i put it back and it eventually died...

what could be wrong? i cant think of anything since the conditions have been the same for the past 45 days...only now did they start dieing off....

Answer 1

My first thought is ammonia poisoning due to over cleaning. When you clean a tank you should use a gravel siphon to clean the gravel as you remove about 25% of the water. Clean in this way once a week to keep the tank stable and healthy.

MM

Answer 2

Your guppies died because guppies when compared to most other fish species, are more frail and subceptible to diseases like the mentioned ''Icks'' or white spot disease.

Therefore, the neons and the orange fish you own was most probably more resistant to diseases and change in water conditions due to tank maintenance and rate of ''good bacteria cleansing'', as compared to the hapless guppies.

The guppies' body could not keep up with the change in environment of the tank while the other fish breeds could ,therefore it might have seemed as though an unknown epidemic had killed off your guppies, specifically.

To avoid this problem in future, try to do a mild water change every once in a while, instead of a full water change in a long time.This would enable even the most sensitive of fish to adapt to the water change since it isn't a big one.

Answer 3

I can't imagine what could be killing guppies and not the other fish! Did you allow the new water to sit until the temperature was correct? Did you use anything besides a clean brush to clean the rocks? Have you checked your filter medium? If your filter isn't working properly, or you somehow killed off your biological filtration (good bacteria), that could cause your ammonia levels to skyrocket. I assume you've tested your water? Did your fish exhibit any signs of illness before you cleaned the tank?
Other than temperature shock, illness, pollution, or the accidental introduction of chemicals, I can't think of anything. I would think any of those would kill all your fish, but I'm not a guppy expert. If the things I listed all check out, maybe somebody else can think of something I haven't. I would reference your aquarium handbook to see if it offers any clues, especially a guppy book, if you have one. Good luck, and my sympathy for your loss.

Answer 4

Never did you mention that you fed them. Just kidding.
Actually, some friends of mine had the same problem. Cleaning the tank killed the fish. Now she hasn't changed it forever and the fish are thriving. I would suggest a magnetised cleaning thing but I don't know what it is called. You can clean the walls of the tank with it.
We have a bunch of fish and they die all the time. If you got new fish recently, they could have brought the ICK (I think that is what it is called), and that would kill all your fish. There is a medicine you can put in the water to kill the ICK and save the fish. If I remember correctly, ICK makes their throats turn red, but I could be wrong. I hope this helps.