Stocking for rimless tanks- how do you keep the fish inside?

lilirose

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Right, so for the past two years I've been watching aquascapers on social media with lovely rimless tanks, filled as close to the top as possible, with no lids, that contain living fish.

All my tanks are rimless. When I set up my 90l rimless community tank, I was heartbroken by the number of fish who leapt out of it in the first couple of months, and heartbroken again when I had to put ugly clips and an acrylic lid on top so my ember tetras would stop leaping to their deaths. Now, I've had a pair of horrendously expensive wild-type Betta imbellis throw themselves out the 1-2mm gap at the edge of the acrylic lid!

I am gutted about the imbellis...the worst part is that I've three other rimless tanks in the early stages of setup. They were custom made. I asked for lids when I bought them, and was told "sorry, these tanks are intended to be open."

So what can I put in a rimless tank that isn't going to jump out of it?
 

Melll

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Hi there,

I know that some marine tank owners use a mesh lid to stop jumpers, have you investigated those? I don`t think there are any fish that definitely will not jump but fish that are torpedo shaped and mainly occupy the uppers levels are more prone to it.
 

Conort2

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I’ve got the mesh on mine. It certainly helps however I very rarely still get the odd jumper that makes it through. Bare in mind though that these are nano fish and are small enough to make it through the mesh gaps if they aim their jump well. I think the only way to be a 100 percent safe is have a proper cover.

Cheers

Conor
 
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lazybones51

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I keep a dozen Ember Tetras and haven't had any jumpers. I lost a guppy, and the Amano shrimp would occasionally climb out. This is an open top tank that's brimmed.

Are you running CO2? Also what are your water parameters, frequency of water changes etc? Could be a water quality issue maybe?
 

lilirose

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@Melll - I have investigated the marine lids. at the time (maybe 8-9 months ago?) I could not find a source that would ship to Ireland. Maybe that has changed, due to the current world situation, a lot of UK retailers refuse to ship here.

@Conort2 - Are you allowed to say where you bought it? I'm uncertain of the rules about stuff like that here.

@lazybones51 - The tank is a 90 liter long (90x30x30cm), low tech as stated before (that is, of course, no CO2), with an extremely well established Hamburg Mattenfilter. Extremely densely planted with slow growers- java fern, several crypts, several anubias, a massive amount of bolbitis, multiple bucephalandra, some moss on the hardscape, and a val which is of course taking over. I use remineralised RO water and do 50% weekly water changes, pH 7.2, TDS running between 75-100, nitrogen parameters are 0/0/5 but often my nitrates are also zero, not due to an uncycled filter but due to the extremely large number of plants. I have not had any fish deaths from anything other than jumping/escaping. Current stock is 12 ember tetras and 12 pygmy cory cats as well as 8 Amanos and immunerable Neocaridina, they have all been in there and happy since the lid was installed nine months ago. The only "problem" is a planaria infestation that I intend to treat when I have a safe place to move my nerite snails.

@milla - the fact that the tank is very shallow (90x30x30cm) means that by lowering the water level enough to prevent any jumping will mean losing a lot of stocking space in the tank...
 

Melll

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@lilirose Have you looked on Amazon, I think Red Sea do some, or have a go at a DIY one. Egg crate with mesh/fine net attached to it. D-D do some as well.
 

milla

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Are you saying that shops such as @Aquarium Gardens lower the water level and only have them filled when the shop is open or videos being made?




By how much?

i have no idea never visitied the place or seen there tanks. but what do they stock them with? Maybe use the same species if tried and tested.

Peersonally i never have the water level above 1.5" from the top. And no jumpers in yaers apart from the odd sucidal cherry shrimp.
 

lilirose

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@lilirose Have you looked on Amazon, I think Red Sea do some, or have a go at a DIY one. Egg crate with mesh/fine net attached to it. D-D do some as well.

My Betta imbellis squeezed out of a 1mm gap, which egg crate certainly has...I really, really wanted to have those fish and had only sourced them two months ago, "gutted" doesn't even really cover it. I suppose not every fish is prone to behaving like that, but as I set the tank up for imbellis and am now realising that it's not an appropriate home for them...I guess I'm looking for other suggestions, that can live with what's already in there?
 

milla

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@milla - the fact that the tank is very shallow (90x30x30cm) means that by lowering the water level enough to prevent any jumping will mean losing a lot of stocking space in the tank...

Ok then you are probably best sticking with the lid or buying / diying a mesh cover or hood of some sort. I honestly cant think of any fish that wouldn't swim over the edge to see whats in the next pond.
 

alto

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Now, I've had a pair of horrendously expensive wild-type Betta imbellis throw themselves out the 1-2mm gap at the edge of the acrylic lid!
Very sad to read this
But
Whoever sold you the wild Betta Sp should’ve warned you that ALL gaps must be covered with cling film
They are notorious for somehow leaping out of tanks through impossibly tiny gaps, and they can do so even after being settled in the tank for several months

There are also (considerable) tank bred Betta imbellis on the market, these seem much less inclined to jump and can lead to confusion over safe keeping of (wild) Betta species

I suppose not every fish is prone to behaving like that, but as I set the tank up for imbellis and am now realising that it's not an appropriate home for them...I guess I'm looking for other suggestions, that can live with what's already in there?
What are the tank dimensions and decor?
Tankmates?

ETA just saw you did answer this above
FWIW I don’t keep tetras with most Bettas, and would especially hesitate with wild Betta sp

(Irrelevant anecdote - I have kept Betta imbellis in an ADA 60P, some carpet areas but mostly taller stems and rock (crevices and overhangs) and wood (again lots of hidden areas)
Tap water is very soft, pH 6-6.4, KH 0-1, GH 0-2
Tankmates were a few chocolate gourami species and some snails
B imbellis was from Franks Bettas - he is one of the most reputable and transparent suppliers of wild Betta species, you can buy a particular fish directly and have it transhipped - not cheap but fish quality is untouchable)
 
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Onoma1

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I used thick ( 10mm) perspex bought of ebay (second hand) with clear acrylic clips ( this type https://www.ebay.co.uk/itm/124183662774). The perspex did bend (slightly) after a while however when the occurred I would just turn it over. This reduced evaporation and meant that fish couldn't jump out.

More recently I have gone for emersed plants and floating plants. My view is that this gives the fish more security and reduces jumping.
 

rebel

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So what can I put in a rimless tank that isn't going to jump out of it?
My approach is to avoid obvious jumpers. You can add some floating plants also. Avoid children jumping next to the tank. ;)

My endlers used to jump out all the time. Over the 3 years, natural selection has caused that to stop!!!

I fill to the rim and ask questions later.
 

lilirose

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Thanks for the advice on the bettas- this pair was indeed tank-raised, and the parents came from Frank's Bettas (they were the next generation on from Frank's). I said "wild-type" to indicate more thoroughly that these were not domestic Splendens, who do best housed alone...I didn't mean to imply that they were wild-caught. I have 30+ years of experience with domestic Betta splendens.

@alto , I also normally would not keep tetras with bettas due to tetras' tendency to fin-nip (oddly, I have always heard that bettas and gouramis together is a recipe for disaster, so have never tried it!). I made the decision to take a chance with the tetras as imbellis don't have long fins. I never saw my ember tetras and my bettas interact at all- they totally ignored each other. The tetras were not harassing the bettas nor vice-versa. The tank itself is jammed with plants, wood, and rocks- there are tons of hiding places and line-of-sight breaks. I really didn't go into this as a clueless noob. ;) But I was not warned to seal the tank top by anyone I spoke to about them.

@rebel - It'd be lovely if you could suggest a few species (preferably not live-bearers) that aren't obvious jumpers. In the past I kept 20 liter betta tanks and a much larger tank with angelfish and tetras- obviously angelfish aren't a possibility with nano tanks, and I'm having bad luck with tetras and (obviously) bettas. I'm looking to stock my other rimless tanks as well, that don't even have the acrylic lids yet, and I'd much prefer not to add them if possible. I have 40+ years of experience with aquariums, and am using RO water and do lots of water changes, so am not afraid of "difficult" species as long as they aren't likely to jump out of the tank, as this distresses both me and my kids. :)
 

zozo

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My approach is to avoid obvious jumpers.

This one in the first place... 💪💪 Research a serious database something like SeriouslyFisch.com.
Then if the description and keeping advice say you need a tight lid because they will/can jump.
Then simply it's a definitively no go for an open-top tank... Then how beautiful they may be, rather choose another fish sp.

Bottom line all fish can jump and it can have a number of causes, some more or less obvious... Observe your fish closely and be cautious when you see signs of flashing, this means it has an itch and could have skin parasites or other illness.

Other things to take into account is character compatibility and the region they like to inhabit. Bottom, Mid and Top region. Some fish have boisterous character and like to chase each other and others. The one chased will try to flee if this happens near the surface, or from the bottom up, a jump is sometimes inevitable and the only way out of the situation. It's a natural behaviour and the fish doesn't realize the tank's footprint and that goes 5 feet down to the floor instead of back into the water.

Fish can be conditioned like all other animals with food... And they are always hungry and also do food competition. Then if you mainly feed them floating food then they'll be conditioned to constantly concentrate on the surface for food. And race towards it the moment it's presented. I've seen boisterous fish jump in a food competition with others. If you have fish like that condition them to forage from the bottom with sinking pellets.

Tank size vs fish size... Fish in panic or excitement can develop lighting fast speeds in an extremely short distance. If it encounters a vertical glass panel at full speed with 3 flaps of the tail fin, then it has only one way to go and that's up and potentially over and out.

For me personally, I discard the inch per x volume rule when it comes to sizing fish for my tanks. Any fish that can not swim 20x its body length from right to left and can not swim 10x its body length from front to back. Is simply too large and completely out of perspective and more like living in a jail cell. Give a fish space and time to develop some speed and hit the breaks again before it bumps into a glass panel. :)

Mating behaviour can trigger jumping, males competing for females... Something that can not always be determined but having too many males vs females in a school can result in more jumpers than in populations with more females than males.

All little things to take into account, but still doesn't prevent a fish occasionally accidentally from leaping out.
 

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