Lids are better because of the humidity they trap. But I would lower it 5 inches and cover the surface in floating plants.

 

I would think 2-3 inches would be enough.

Edit: rimless tanks looks amazing! If your really worried, you can get white craft mesh and make your own lid or get some plexiglass that can keep the rimless look.

 

Floating plants.

 

I think like anything else it depends on the Betta & how close to the side the Betta is. My girls go crazy jumping up & over each other when its dinner time but so far nobody has gotten any real air. I would put some kind of light weight cover on it to just be safe.

 

I have 2 open top tanks and two with tops. Overall I prefer open top as they look better. I have never had a fish actually jump the tank and the glass on one of them only reaches a few Cm above the water line, the other alot above.
I used to have a jumping plakat that jumped his seperator.

I think 2-3 inches are fine.

 

About 3 inches should be plenty enough to prevent them from jumping out. Mine used to jump until they got older.. one still does, she'll jump into your hand if you lower it enough, as well as jump out for food. Don't need floating plants.. if they want to jump they will find any opening and do so.

 

I have had mine jump 5" high (one did who holds the record in my house for the last two years) and 10" across :lol: however that was for food and not much else for reasons. 2-3 inches is fine, and recommended especially for those happy jumpers.

 

I have had mine jump 5" high (one did who holds the record in my house for the last two years) and 10" across

That's insane.

 

They were insane :lol: every jump they made I measured... Average jump was 2.5-3 inches, record 5

 

Its still safer to have floating plants plus Bettas love the roots they can hide in.

 

Well, here's my sorority in action: http://www.youtube.com/watch?v=d1baYtkoqFE

You can see the white female gets pretty good air, she could easily jump 6 inches at feeding time. I normally keep the lid on that tank when feeding for this reason.

 

Water Sprite is a good plant and I am pretty sure dwarf Water Lettuce and frogbit.

 

awww I wish u could keep males together like that I always feel bad for Sushi being all alone. oh well...cute fish/tank by the way

 

If you got a ten or twenty gallon some Cories or WCMM.

 

A lid is an absolute must, my girl can jump a good 3 inches! She did jump out of her tank once (through a tiny hole barely a half inch big in the lid) and was out of the water at least a half an hour. She's ok, and now almost 3 months later, you would never even know she jumped.

But please, please, please get a lid and cover all holes with something breathable so you don't have to go through what I did.

 

Floating plants can act as a lid. Why dont you want a lid?

 

The whole point of a rimless tank is to have nothing obstructing the view of the tank, including covers on top. And while I know it's stupid to not have (esp w/ bettas potentially jumping) I would rather lower the water level to a safe distance from the top rim rather than put a lid on it.

 

You'll need to lower it at least 5 to 6 inches then. Like I said, I know my girl can jump at least 3, but others have had some jump much higher.

 

I would say 3 inches with plenty of floating objects will work.

 

Please note, long finned males VS females or PLAKATS will always vary. My females can jump very well. One of my fry eluded the net, cup, ladle, by jumping pretty dang high - and she is only 7 weeks!

However none of my males get their full body out of the water.

Find some nice acrylic, drill holes in it and perhaps make a feeding hole by remount a piece and attaching it via hinge. Keeps it clean and clear looking without a bulky hood, but that way you won't worry. I don't have lids on my male's tanks. But I also know my fish individually - and which ones are trouble makers (aka failed wannabe elvolutioners :lol

 

I like the using the Mesh Ideas.

 

Floating plants do not stop females, especially if it is feeding time.

My girls don't go for height, they go for length. I have one girl who went through this weird phase where she would jump and stick to the wall of the tank briefly.

 

:lol: Mine did that. One would actually get my attention by jumping out against the glass, sticking, plopping back in the water. And repeat.

 

Floating objects certainly don't stop my girl from jumping.

 

Well, to summarize: it varies from betta to betta on how high they may jump. If you get to know your fish and their behaviors first, then you will know the appropriate course of action.
Until then, lower the water approx 2-4 inches and go from there.

Also, post pictures of your tank please! I love rimless tanks. <3

 

Well, to summarize: it varies from betta to betta on how high they may jump. If you get to know your fish and their behaviors first, then you will know the appropriate course of action.
Until then, lower the water approx 2-4 inches and go from there.

Also, post pictures of your tank please! I love rimless tanks. <3

Here you go....enjoy. BTW the water is about 1.5 inches from the rim top in these pics.

 

I expect much of that tonight. I just bought frozen brine shrimp.

 

Depens on how many floating plants and what kind.

 

Oh it looks so good so far!!
I can't wait to see once you get more plants and stuff in there.