# Grass carp minnows dying



## BretSV (Aug 8, 2012)

Hello all,

I recently started my first fish tank to introduce my 3 year old daughter to river wildlife (little did I know I was stepping into an addiction of my own in aquariums). It is a 10 gallon tank and I have only been stocking it with rocks, plants and species we have caught from the river. We've had a crayfish and two mosquito fish living well in it for about a month. The other day we caught 6 very small (1"-4") grass carp and all died one by one over a period of 3 days. One of them the entire back half of their body turned pale and they died. The other one had one eye get really large and discolored. The others started swimming upside down and eventually just stopped moving and were consumed by the crayfish.

These fish are super abundant in our river but quickly dying in my tank while other small fish seem fine. Any thoughts? I'd love to keep some more of these but don't want to repeat the same and kill more fish.

Thanks.


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## susankat (Nov 15, 2008)

Adding so many fish at once caused an ammonia spike in that small of a tank. For 4inch minnows I would use at least a 20 long and set it up naturally and do weekly water changes on it.


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## BretSV (Aug 8, 2012)

Thanks. Got a 20 gallon tank from a friend today and will set that up and try again with some more of these guys. 

I also realized that although my mosquito fish eat the flake food, the carp were not touching it. The one that is left I fed some crushed up oatmeal since that is a common carp bait and he ate it up ferociously, so the fact that they weren't eating could not have helped them.


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## NeonShark666 (Dec 13, 2010)

Sounds like the WQ in ther river is better and/or different than in your tank (lower temp, lower Nitrate and higher O2).


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## navigator black (Jan 3, 2012)

Grass carp aren't a good educational fish unless you want to teach your kids about death.
To begin, educationally, it is an invader - not native to your river unless you are in China. It is a really destructive invasive species. 

It is also a huge fish - and one you can never return to the wild when it outgrows your tank (a rule of thumb for native fishkeeping is to never release back - aquariums have different diseases, bacteria etc than the wild, and it is responsible to keep them apart).

One grass carp needs about 100 gallons with water changes of 50% every second day. It is an intestine with eyes. It eats huge amounts of plants - aquatic roughage which it digests poorly and drops out the other end. It's like putting a cow in your aquarium, in effect.

You'd be hard pressed to find a worse fish to put in a home aquarium - massive pollution problems, little educational value and uuugly.

Go for the native minnows. I don't know where you are, but the south of the US has astonishing fish - just look at the natives section here. There's a poster named dirtydutch who has found things I'd love to be able to get where I am.


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## Kehy (Apr 19, 2011)

Even in northern areas of north america, there's flathead and fathead minnows and banded killifish that could work in tanks (that I know of). Remember to cycle your tank (allow beneficial bacteria to build up and convert ammonia and nitrites) and plant heavily.


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