Why did my fish die? Help!!!?

[Herbert]

I just bought a fish tank about a month ago. I changed the water today as it was dirty, using the vacuum hose to remove the dirty water. I did not empty the dirty water completely as the fish were still in the tank. I left 25% of the old water and I begin to fill the tank with fresh water using the water hose. I still had the vacuum hose inside while filling the tank with fresh water to make the water appear more cleaner. The fish appeared to be fine until the fish tank was full again and I noticed some of the fish going into some sort of shock. Trying to jump out it seems. When I turned off the water hose and remove the vacuum hose, I notice that at least 5 of my fish were floating upside down. What did I do wrong? Was it too much pressure? Was the water too warm? Help!!!

[kyley]

your supposed to get rid of the chlorine. thats why they died. take your fish out in a seperate container then buy some water cleaner for fish tanks. put some water in a bucket after emptying you tank then put the ammount your supposed to of the cleanser stuff. then put the water in the tank and put your fish back in. easy (:

[Kaylaa973]

you're supposed to get rid of the clorine. take the fish out a put them in another bowl to do this.
sorry to hear bout the fish :( :)

[BoomBoom200]

Sorry man but you most of read it wrong.
You are only supposed to take out 25% of the water.
You took out to much water causing your tank to re-cycle. When you take out more then 30% of the water to much beneficial bacteria that fish need to survive is taken away.
Your fish died under stress and the fact that the water levels started to change during it's cycling period.

Hope this helps!
Good Luck!

EDIT:
Some people said it was chlorine. Did you use a water conditioner?
This will get rid of chlorine, metals and copper.
Also put the conditioner in the bucket not in the tank after you add the water.

EDIT:
half of these answers or more don't make any sense.
I poor my water into my tank from at least a foot up and I have a tone of fish The only way pressure will kill them is if are dumping water into the tank for more then 5 minutes (fish can live out of water for 6 minutes).

EDIT:
Someone suggested a algea eater.
They do not clean the tank. They eat algea and some left over fish flakes.
They will also create a lot of waste which would cause your tank do be more dirty. Also a a algea eater (Plecotomus) need a minimum 55 Gallon tank since they reach 19"

[DueMay27th2010]

i agree with the first answer. The water temp was too cold

[Maureen301]

It could have been the stress of everything going on. It could have been the rapidly changing temperatures of the water. Perhaps your water didn't have enough oxygen in it.

As for dirty water... Try buying an algae eater.

[KITCAT]

You put to much pressure on them any way it normal for fish to die get over it!

[wonderboy321]

common reasons for fish sudden death syndrome:
1. overfeeding-No#1 cause of fish death
2. contamination of the tank water by external forces(bacteria, oil, etc on hands, on instruments like fish net or rocks.
3. you said FRESH WATER- if this was tap water, that contains chlorine, salt, and other contaminents from the pipes it travels over. Suggestion-if you do use tap water to fill your tank, let it sit at least 24 hours before you put in to tank.
4. improper PH levels in the water-.do some research on the pH scale, which essentially measures the acidity of something. Fish Water is very vunerable to changes in it's acid levels.
Hope this helps

[KylieAnne140]

that was a big change, you should be changing 25% every week. the temp change was probably too big. also going from horrible water to clean water. did you remember to add dechlorinator?

when you allow the tank to become dirty, the important things are already WAY too high. fish don't care how dirty the water looks, what matters to fish is the level of ammonia, nitrite, and nitrate.you should keep these from getting high by changing 25% each week instead of a large water change less often.

[hmx_mail409]

Changing that much water will not cause your fish to go into shock and die within minutes. Even if changing all that water got rid of a good portion of your beneficial bacteria, it will not ever cause the fish to outright die in seconds. And by the way, the bacteria lives in the filter and gravel and decorations, so changing the water won't remove enough to cause serious harm. Many aquarium books will tell you that it's safe to change up to 75% of the water without issue. If you did uncycle your tank, you'd more likely see your fish become sick with ich or fungus about three weeks later.

In any case, the most likely culprit is too drastic of a temperature change between the water from the hose and the water in the aquarium. If the water was too warm, the fish will kind of look like they're having a seizure and then die within minutes. If it's too cold, they would really just kind of slow down and seem lethargic until things warmed up, so too warm is probably the case. This depends somewhat on the kind of fish you have (some, like angelfish and neon tetras are much more sensitive to temperature changes and may die from the cold, but it wouldn't be within minutes). If chlorine was the culprit the fish would come to the top of the water and gasp for air off the surface. Temperature was it.