# giant danios swimming at surface



## Mr_Bubbles (May 10, 2011)

Hey everyone,

I've noticed my giant danios seem to swim at the surface and act hyper, i'm assuming they're gasping for air? While gone one night for a few hours I had one jump out and die  I have an air pump on at night to help aerate, but it doesn't seem to be helping much. I have a drop checker and it's been staying within the green, does anyone have any suggestions?

Thanks!


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## jaidexl (Sep 18, 2006)

Maybe increase surface agitation. Are they gasping later in the day? If so, it's possible your bubble rate is a bit more than the plants can use up in a day, since a DC can take a few hours to show actual CO2 levels, a buildup later in the day before lights go out could be missed by the DC. See how far you can reduce BPS while staying in the green, or have it shut off a little earlier.


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## Mr_Bubbles (May 10, 2011)

well i have 2 HOB Filters and have 2 small airs stones going, does it matter how close to the surface they are? and the fish are fine until the lights go out at 10pm, could it be the PH shift from the Co2 turning off, or? None of the other fish seem phased at all, just the danios


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## jaidexl (Sep 18, 2006)

That should be plenty of agitation, I would almost doubt CO2 is the problem. Are you saying they do this after lights out? I have a few species that hover at the surface when they sleep, I have no explanation for your hyperactivity though. Could they be getting spooked by motion in the room and ambient light? Now that I think of it, if I go in my dark room right now and flick the bathroom light on, I can see tetras tweaking out in the tank.


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## jaidexl (Sep 18, 2006)

In my experience, gassed fish won't move around erratically, they sit still with their mouths breaking the surface or just under it, breathing heavily.


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## jaidexl (Sep 18, 2006)

Mr_Bubbles said:


> could it be the PH shift from the Co2 turning off


Hmmmmm, seriously doubt that, the only thing that shift entails is a decrease of CO2. CO2 related pH shifts don't bother fish, only excessive CO2. An alkalinity related pH shift can kill fish only because it usually includes a GH drop which can cause osmotic shock.


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## Mr_Bubbles (May 10, 2011)

Is this possibly just their nightly behavior? I do have ambient light on sometimes, but they seem to stay more around the middle during the day, and then act like this at night, though they are generally quite hyper most of the time, but at night they usually calm down a couple hours after lights are off, i just worry for their health, if it's normal then that's fine. I know their said to be jumpers, but figured they'd only jump out if there were problems with their environment.


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## jaidexl (Sep 18, 2006)

Here's a theory.. Could be they're just shocked from the lights flipping off all of the sudden. I have some SW reef fish that see dark as the time when predators are out, so when the light flicks off they're quick to find a hole in the rocks. Maybe it's this type of behavior you're seeing, sort of a darkness flight. It helps on the reef tanks that there are moonlights and actinics which stay on an hour after the white bulbs go off, this gives the fish some chill time to prepare for darkness. Maybe if you keep the room fully lit during lights out on the tank, then shut them off an hour later, they won't get spooked.

I've never kept the giants, so not sure about they're behavior. I know I can't pull one image from my mind of a zebra danio ever standing still. I used to make them chase a laser at night.


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## xmas_one (Feb 5, 2010)

That's what danios do. Seriously look it up. They tear around at the top and jump out.


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## Mr_Bubbles (May 10, 2011)

ok, i'm gonna assume this is normal behavior, i know they're known for swimming at the top and for jumping, just seemed weird that they do it at night mostly


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## jstehman (Dec 13, 2010)

My giant danios act the same way yours do with or without CO2 addition. They never stop moving and "gasping". I started with 3, but one jumped out, don't know why. But I did make sure that the tank was completely covered.


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