# Lethargic Fish After Water change



## Toxan88

Today, I changed the water in my tank for the first time. The tank is 10 gallons, has 2 mollies, 2 platies, 1 swordtail, 3 tetras, 2 tiger barbs, and an albino cory cat. I removed 20% of the water and replaced it with treated tap water. Both before and after the change, water parameters were fairly normal. However about 30 minutes after the new water, 1 of the tetras started acting strange, swimming with it's mouth to the surface. The tetra eventually died. After I removed the former tetra, i noticed the the other fish were acting rather lethargic or sluggish, with occasional bouts of activity. Can someone please help me remedy this problem before I kill any more fish? Also, I did not plan on keeping these fish in this tank, and was holding the barbs and tetras for a friend. Who was going on an extended vacation.

Thank you


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## jasonmk1j

Did the temerature in the tank drop significantly when you added the new water? when I did a 50% change on my 70l tank my Betta was looking really unhappy, then I notiiced the temp had gone down to 16' I took him out and put him in the bucket of old water til the temp stabilised but that took several hours. I always make sure any new water is as close tank temp as I can get now, apparently sudden temp changes can be very bad.


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## zero

did you treat the water with dechlrinator? also is the tank cycled?


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## beaslbob

Check your ammonia immediately.

I did some maintenenace on a marine tank a few years back and noticed similiar things. After 1 fish died 8 hours later I discovered ammonia pegged the api test kit. I must have inadvertantly added a toxin.

So to be safe check your ammonia.

my .02


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## majerah1

How long was it since you did a waterchange?To me it sounds like you are overstocked for one,but the mouth to the surface is a sign of a PH drop or lack of oxygen.Sometimes when we let our tap water sit the ph will stabilize as something different,either higher or lower than it started.In which case some people have to age their water because of this.You could check it with a ph test out of the tap,let it sit and come back a few hours test again and then come back the next day and check again.Temp is also a factor,if it was cooler or warmer it would cause stress as well,depending on how fast and how much of a difference it is when added.


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## Toxan88

Lost another of the tetras during the night, but the rest of the fish seemed to have perked up, except for the remaining tetra. I conditioned the tap water, as well as let it sit for a few hours , so that it could reach a similar temperature to my tank. Unfortunately, my test strip doesn't check for ammonia, which I didn't notice before. I'm going to do another water change to make sure its not ammonia causing the problem.


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## Chandavi

What type of dechlorinator are you using? Prime? Other?

Try taking a sample of your water to a local fish store so that they can test ammonia, nitrite, nitrate, pH, and water hardness. Most will do this for free, especially if you do business with them or have done so before. I would advise getting yourself an API Freshwater Master testing kit asap if you do not have a way to test each of these metrics.


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