20 Gallon Tank Glofish tetras bullying guppies? Help!

Anyone have experience with Glofish tetras being bullies? I had 5 small/medium ones and 3 male guppies in a 20g (1/2 planted 1/2 silk) for almost a year. A few days ago I found one guppy is dead, I figured ok it’s nibbled on a bit but that’s expected. Then I notice the other two guppies have missing scales and their fins have bite marks on them!!! I moved them to a small hospital tank and am treating them with medicine (they are doing better thank goodness!) but I don’t know what happened to suddenly make the Glofish turn mean! They were fine for so long all together! I’ll be running to buy a bigger tank for my guppy guys in the next few days but I feel bad for them in the tiny hospital tank in the meantime. The water parameters are right on point, the heater is working, they’re fed well so there’s no competition there, and there’s been no changes to the tank (except vacuuming) in at least 6 months. Are there warning signs I should have noticed earlier? I feel horrible for my babies being hurt

 

It's not uncommon for tetras to fin nip other fish if they don't have enough of their own species to hold their attention. Six is usually given as the minimum number to avoid that, but more is always better (space and other conditions permitting).

You might try getting a few more of them to see if that helps, but if not you may just need to keep them alone in the tank. If you want a little variety you can get either white skirt tetras or black skirt tetras. They're all color variations of the same species as the glo tetras.

 

It's not uncommon for tetras to fin nip other fish if they don't have enough of their own species to hold their attention. Six is usually given as the minimum number to avoid that, but more is always better (space and other conditions permitting).

You might try getting a few more of them to see if that helps, but if not you may just need to keep them alone in the tank. If you want a little variety you can get either white skirt tetras or black skirt tetras. They're all color variations of the same species as the glo tetras.

How many more should I get to stop the bullying? 2-3? Idk how many can fit in a 20g?

 

How many more should I get to stop the bullying? 2-3? Idk how many can fit in a 20g?

Two or three more shouldn't be a problem. If it's a 20 gallon long instead of a standard 20 you could get a few more than that.

 

Two or three more shouldn't be a problem. If it's a 20 gallon long instead of a standard 20 you could get a few more than that.

I can do that. And no it’s just a standard 20, was on sale when I was looking for a 10 years ago and couldn’t pass up the price. One more question: will the 2 guppies be ok in a 5g? I think I have a spare 5.5 hidden in my closet. Or do I need a bigger tank for more guppies?

 

. . . One more question: will the 2 guppies be ok in a 5g? I think I have a spare 5.5 hidden in my closet. Or do I need a bigger tank for more guppies?

I have three guppies doing just fine in a heavily planted 5.5 gallon tank on my desk at work. By all indications they're doing just fine.

 

I have three guppies doing just fine in a heavily planted 5.5 gallon tank on my desk at work. By all indications they're doing just fine.

Thanks so much! I’m so happy to hear that, I’ve been so stressed about what to do with my boys! You are the best!

 

I don't know why they "turned mean" but I really don't expect that adding more will make that go away at this point. Probably just the size of the tank now that they are mature. Get more if you want to but I wouldn't put the guppies back in with them. I kept a few guppies in a 5 many years ago and they did fine. Started with 3 and never had more than 5-6

I don't know how much the Glo-fish differ, but I have 6 Black Skirts in my 75 gallon tank along with some Cory's and one Angelfish. The Skirts sometimes poke at each other but almost never make actual contact. They never even look at the Cory's, and wouldn't dare try to nip at the Angel: she sends them packing whenever they get too close around feeding time.

 

I don't know why they "turned mean" but I really don't expect that adding more will make that go away at this point. Probably just the size of the tank now that they are mature. Get more if you want to but I wouldn't put the guppies back in with them. I kept a few guppies in a 5 many years ago and they did fine. Started with 3 and never had more than 5-6

I don't know how much the Glo-fish differ, but I have 6 Black Skirts in my 75 gallon tank along with some Cory's and one Angelfish. The Skirts sometimes poke at each other but almost never make actual contact. They never even look at the Cory's, and wouldn't dare try to nip at the Angel: she sends them packing whenever they get too close around feeding time.

That’s the weird thing, the Glofish are all about 3 years old. Fully grown and mature which is another reason I was so confused

 

How long were the guppies in there with them?

 

How long were the guppies in there with them?

A few weeks under a year. I got them for myself for my birthday last august. Literally no problems before or after the guppies until a few days ago.