open top suicidal jumping fish

[waddo]

I have a 60cm tank that is only 20cm tall. From time to time, usually at night, a lemon tetra leaps to his death.

Any way to solve this problem?

[mitchfish9]

Without a glass top or hood of some sort? Not really. Maybe more plant cover can help but it's certainly not 100% effective.

[Aquatic Delight]

people have recommended egg crate to me before. i've never used it, but i've been told it works

[Bubba Shrimp]

an egg crate over the tank? That's weird

[iant]

try lowering your water level an inch or so to keep them from jumping over the rim. then they can jump all they want. Could also be related to water quality it being a small tank. fish are known to jump out of bad water

[l8nite]

Originally Posted by Bubba Shrimp

an egg crate over the tank? That's weird

not the stuff your eggs come in at the store...

this:

[Aquatic Delight]

thanks l8nite.

[Cthulhu]

If you put that egg crate between the water and lights, it can cut light by 30%.

I have a hood with open sides/back. And I used to have a wrasse, these fish jump a lot, and they can jump quite high. I used wedding veil fabric to make the hood wrasse-proof by closing every open space on the sides/back. I've seen this net save the life of my wrasse a few times as he jumped right into it then fell back in the water.

[lullafishi]

Originally Posted by l8nite

not the stuff your eggs come in at the store...

this:

Hahaha, I may have also been guilty of picturing produce egg crates. XD

[xiaoxiy]

Originally Posted by Cthulhu

If you put that egg crate between the water and lights, it can cut light by 30%.

I'm not sure that's true. According to Hoppy, window screening will reduce your light by 30-40%.

[Bushkill]

Eggcrate doesn't block light penetration. It actually focuses it. Downward. Remember it's not being used for it's intended purpose. So that wat it actually does is decrease the coverage or "spread" that you get from non-single source lighting like T-5 bulbs.

While it can stop jumpers it doesn't get them all. Something like a lemon tetra will eventually find the openings. Some will actually end up right on top of the eggcrate and dry up there.

If you're good with some basic tools, go to one of the big box stores and buy a kit to build your own window screen. The only tools you need is a hack saw and the spline tool to push the spline into the groove to retain the screening. Don't use window screening. That WILL decrease light penetration and dramatically so. Go to a store that sells pond supplies and buy pond netting with 1/4" mesh and use that in place of window screening in the frame you've built.

Sound involved?

The concept came from SW tanks that run open-top by necessity.

Other than the screen covers, glass is your best bet and it minimizes evaporation.

If you can live with light constraints of eggcrate you can crazy glue some bridal veil netting to it to close the gaps in it. You can also cut some of the grid out of the middle to decrease the light focusing effect to some degree, thus making it something of a frame for the bridal veil netting.

[fishwater]

Originally Posted by Bushkill

While it can stop jumpers it doesn't get them all. Something like a lemon tetra will eventually find the openings. Some will actually end up right on top of the eggcrate and dry up there.

This. I lost two marbled hatchets through those little holes . I since replaced the crate under my light with a fully sealed top. I am using a small piece of the crate towards the back of my tank to allow my auto-feeder to drop food through a couple of the holes. I sealed off the rest of the holes by wrapping saran wrap around the remaining openings. I figure If I lose another fish through the 2 little holes that help keep him alive (food), then the fish must really not want to stay wet .

You could try to find a piece of plexiglass or acrylic and cut it to fit the top of your tank.

[wendyjo]

I also use breathable fabric (along with velcro) to cover up each and every hole in my tank top to prevent fishie suicides.

[fusiongt]

I say lower the water level a bit (though you'd be surprised they can still make their way out), or possibly just live with it and get new fish less prone to jumping when there's less of them. I know it's a mean thing to say, but I've had this experience and putting an ugly DIY top (yea even if it's as good as you can make it, it's still not as good as rimless) just isn't the look most of us try to go for.

Now I lower the water a bit more than I would before but most of my jumpers aren't there anymore and I'm leaning towards getting more fish that won't jump as much. Tetras, especially active ones like what you had, can and will jump... people will say something is wrong with the parameters or they got spooked, but I've literally sat and watched from afar a fish jump out for no reason from a well-established tank. Perhaps fish on fish chasing each other caused it. Whatever the case, changing the type of fish you have will make a difference.

[Bushkill]

To give some thought to the reasons for jumpers, there are some simple reasons. And yes, some fish will jump no matter what you do.

I think the majority of fishy-cide by jumping is caused by photo-shock. I think in most cases, folks have their lights simply come on full strength at a certain point in the day either manually or via a timer.

If you've spent any time on the SW side of the hobby, you may have noticed that there are a whole boatload of moonlight simulation vehicles out there now. Since that side of the hobby has evolved to emulate natural cycles more and more over the last 15 years, the FW side hasn't paid quite as much attention to the effects of lighting cycles on fish and other organisms.

What I'm inching my way towards here is the notion that lighting should be brought to full strength in steps, wherever possible. I use blue actinic lighting to get the fish in the fish room up and about for breakfast (I'm out the door early!). Just a simple bare flourescent fixture that doesn't have to come close to covering the length of the tank. There's no jitters, no dashing around, nobody looking dazed and confused and best of all no jumpers. They adjust to it calmly over the first half hour and are ready and raring for breakfast before I leave the house. The timer is set to go off once the daylights come on. Conversely, the opposite works just as well before lights out at night.

It's not expensive. As an example, I have a simple 2 foot flourescent strip light over a bank of 3 20G's on a simple timer. About a $30 investment for everything. The limited hours on the bulb will give a service life of anywhere from 3 to 4 years. Remember it's not intended to grow plants. There are tiny and inexpensive fixtures made for nanos that will serve the same purpose.

Will it stop 100% of jumpers? Absolutely not. There's lots of reasons for it. But photo-shock is just one that has a pretty simple fix. If they don't jump, some fish just smash into things in that first second, causing a whole different set of issues from the fishy-cide leap.