Covers on an aquarium...

The more I have been reading on setting up aquariums the more I see that some people have to cover - no screen, no glass, no anything.

Don't the fish jump out?

Does this work with native minnows or are they too jumpy?

If you have no cover should you not fill the tank to the top?

This seems like a good way to go as it would keep the aquarium temperature a bit cooler.

Andy

I don't have a lid on my darter tank or my "swamp" tank. PM me for more details.

My 40breeder tank is lidless and I have lost F.notatus and F.olivaceous. I seem to remember others saying that they had problems with Lythrurus sp., as well as crawfish buying the farm.

Leaving a gap at the top of, not filling, the tank may work at four or greater inches but that method is not aesthetically pleasing.

The lidless method certainly would keep temps lower if you had a high w.p.g. count or were using incandescent bulbs, but the lid vs. lidless temperature difference in these situations would be (in my opinion) nominal - not to mention the light loss.

I went lidless on this tank so that I could have emergent plants and play around/experiment with the tank structure and powerhead flow often. Window screening would work well if you wanted the same "airspace" and could be custom cut at your local hardware store on the cheap.

I don't think that my topminnows would have jumped if they had not been "spooked":
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I go topless with planted tanks. I somewhere read that the glass reduces the lighting. Even if the clean glass doesn't cut much light, the glass is never really clean, at least for someone with my lack of house keeping skills. I also like having emergent plants growing out of the water.
You definately can lose fish. Some species are worse than others. I couldn't keep top minnows from jumping. I don't think they spooked, they just like to jump. I've lost a few blacknosed dace too. Of tropicals I've kept, swordtails were the worst, especially the males.
Having lots of floating vegetation covering the surface keeps some of the spook-prone species from leaping to their death.
The other downside of going topless is evaporation. Obviously it's worse without a cover. I'm lucky in that I have access to free distilled water to replace evaporated water. If you're always using your tapwater to make up for evaporation, your water gets stronger and stronger in regards to disolved minerals and nutrients.
I believe I benifit in my planted tanks although I've never done a controlled experiment to compare results. If not for the plants, I don't think it'd be worth going topless.

Like this?

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I use a screen top over my 10 gal but my 2.5s have glass lids--the nice thing about the lids is you don't have to top off the tanks constantly due to evaporation... also I hear my topminnows jump from time to time, fwiw