Magic Number

[Guppysnail]

On 7/9/2021 at 12:57 PM, Bobbie said:

Oops didn’t notice this until now, sorry! This got a bit long and ran away from the point of your question because it seems I don’t know when to shut up. 
 

My zebra danios have never been a tight bunch and will happily stay away from each other while exploring the tank. Really the only time I see them in a group is when they’re eating an algae wafer or they’re sleeping. 

For the few weeks I only had 3 danios, they stuck together and never seemed to stop moving (if they got spooked I’d hear them crashing against the glass trying to get away) - they were also somewhat aggressive to each other, lost a lot of their colour, and were hiding most of the day. It really wasn’t fun to watch compared to how they had been. I’d noticed them becoming more skittish and fearful as the numbers had went down, but I didn’t expect the change to happen within days. 
 

Once I bought the extra danios and added them in, it was like a switch was flipped. At first they were all in a very tight group and were jumping quite a bit, but after a few hours they settled back down and split into pairs or trios to wander around the tank. For a week or so they harassed the snails, which hadn’t happened before, but that mostly stopped once they realised they can’t bite through shell. 
 

I’d often read that zebra danios always hang out in the middle-upper levels of the tank and don’t spent too much time down the bottom, but for the 5-ish months I kept them as a species-only tank they actually preferred to stick close to the substrate and only went near the surface if there was food floating. Once I added the corydoras they started spending more time away from the substrate but they’ll still often go and swim around wherever the corycats are chilling, especially the males - even when there’s no food. 
When I added the male betta to the tank they spent a day or so lurking in a corner watching him warily (although the corycats didn’t care at all) but now they’ll happily eat with him and don’t seem to mind when he joins their group at bedtime. 
 

Some other interesting things I’ve noticed is that the danios love to rip up the roots of every java fern I try to grow in the tank, it’s the first thing they do every morning when the lights go on. Also, whenever I dose the tank with API white spot cure the corydoras don’t act differently at all (even though the packaging says that catfish are sensitive to it so I only put in half the recommended dosage) but the zebra danios lose their appetite and become very lethargic until I’ve done a water change or two. I’m not sure why, and I’ve never seen anyone else mention it. 
 

Overall zebra danios are amazing and a super underrated fish, and I’d love to put a large group of them in something like a 50 gallon or larger to see how their behaviour changes. 

I was setting a tank last year but could not get my fish for a few months so microcritters getting overpopulated was a concern. I have a dynamite relationship with my LFS so I borrowed a few zebra danios until I could get my fish.  after QT I put them in and they hunted in the substrate hovering looking for things to eat. I think Java fern roots being feathery they may think micro worm?

[KentFishFanUK]

On 7/9/2021 at 5:57 PM, Bobbie said:

Oops didn’t notice this until now, sorry! This got a bit long and ran away from the point of your question because it seems I don’t know when to shut up. 
 

My zebra danios have never been a tight bunch and will happily stay away from each other while exploring the tank. Really the only time I see them in a group is when they’re eating an algae wafer or they’re sleeping. 

For the few weeks I only had 3 danios, they stuck together and never seemed to stop moving (if they got spooked I’d hear them crashing against the glass trying to get away) - they were also somewhat aggressive to each other, lost a lot of their colour, and were hiding most of the day. It really wasn’t fun to watch compared to how they had been. I’d noticed them becoming more skittish and fearful as the numbers had went down, but I didn’t expect the change to happen within days. 
 

Once I bought the extra danios and added them in, it was like a switch was flipped. At first they were all in a very tight group and were jumping quite a bit, but after a few hours they settled back down and split into pairs or trios to wander around the tank. For a week or so they harassed the snails, which hadn’t happened before, but that mostly stopped once they realised they can’t bite through shell. 
 

I’d often read that zebra danios always hang out in the middle-upper levels of the tank and don’t spent too much time down the bottom, but for the 5-ish months I kept them as a species-only tank they actually preferred to stick close to the substrate and only went near the surface if there was food floating. Once I added the corydoras they started spending more time away from the substrate but they’ll still often go and swim around wherever the corycats are chilling, especially the males - even when there’s no food. 
When I added the male betta to the tank they spent a day or so lurking in a corner watching him warily (although the corycats didn’t care at all) but now they’ll happily eat with him and don’t seem to mind when he joins their group at bedtime. 
 

Some other interesting things I’ve noticed is that the danios love to rip up the roots of every java fern I try to grow in the tank, it’s the first thing they do every morning when the lights go on. Also, whenever I dose the tank with API white spot cure the corydoras don’t act differently at all (even though the packaging says that catfish are sensitive to it so I only put in half the recommended dosage) but the zebra danios lose their appetite and become very lethargic until I’ve done a water change or two. I’m not sure why, and I’ve never seen anyone else mention it. 
 

Overall zebra danios are amazing and a super underrated fish, and I’d love to put a large group of them in something like a 50 gallon or larger to see how their behaviour changes. 

I have to admit danios have never wowed me so haven't considered them much. Saw an albino(?) version at the LFS yesterday and they looked real nice. And this is all good info! Will try and remember it if I ever keep some danios. Need to start a notebook with all this useful information people post! You don't hear about stuff like the effect of that medication on generic care sheets you see online. 

I hope you do your huge group in a 50 one day!

[Bobbie]

On 7/9/2021 at 10:35 PM, KentFishFanUK said:

I have to admit danios have never wowed me so haven't considered them much. Saw an albino(?) version at the LFS yesterday and they looked real nice. And this is all good info! Will try and remember it if I ever keep some danios. Need to start a notebook with all this useful information people post! You don't hear about stuff like the effect of that medication on generic care sheets you see online. 

I hope you do your huge group in a 50 one day!

Those were probably the golden variation, I’ve heard they become a lovely pinkish colour as they grow up! I’ve got 2 regular danios that are quite a bit more golden than the rest, and it’s interesting to see where the golden mutation started out before it was bred for. 
 

And yeah I’ll need to start a notebook of advice too, this forum is a goldmine of information. 
 

I’m saving up for at least a 29g but what I eventually get will really depend on how much space I can clear, been really looking forward to whatever I eventually do with the new tank.