What are your thoughts on this matter? Moving fish from bigger aquarium to smaller?

Hello everyone. I bought 6 diamond tetras a few weeks ago to put in my 55 gallon tank with cories, rummy nose, and a honey Gourami. They are very aggressive with food, to the point where they steal all of my cories wafers when lights are off. And when the cories are on them, they butt them out of the way to snatch them up. I don’t like fish messing with my cories at all. I have a 20 gallon with 5 zebra Danios and 8 neons, would this be a better set up? I kinda feel bad moving them to a smaller tank, but they do not leave any food for my other fish, and are aggressive to my cories. What do you think I should do?

 

Hello everyone. I bought 6 diamond tetras a few weeks ago to put in my 55 gallon tank with cories, rummy nose, and a honey Gourami. They are very aggressive with food, to the point where they steal all of my cories wafers when lights are off. And when the cories are on them, they butt them out of the way to snatch them up. I don’t like fish messing with my cories at all. I have a 20 gallon with 5 zebra Danios and 8 neons, would this be a better set up? I kinda feel bad moving them to a smaller tank, but they do not leave any food for my other fish, and are aggressive to my cories. What do you think I should do?

I don't see a problem with it.

 

You should do it and then let us know who wins the "top, bottom, middle" battle. This is always interesting to me in my own tanks when I move schools. I don't think that sounds overstocked, but watch your numbers for a week incase you mini-cycle.

 

I recently moved my neons to a smaller tank, but that was for their safety, one disappeared and I suspected one of my fast-growing Cichlasomas was the culprit. They hid at the back of the new tank for several days but are fine now. Diamonds are bigger I know, but it should work ok.

 

20 tall or 20 high?

 

At the end of the day, to keep corys safe it's the most humane option. I had some issues in my large tank with some cherry barbs acting out (yeah, tiny angry fish) so I moved them to a 20g for a month. When I put them back, boom, no more problems. I guess you can even give fish a timeout.

 

Dioman tetra are small and the school should be fine in a 20 gallon. I suggest that you move the danios to the 55 gallon at the same time. Danios are super active and they will use the entire 48 inches of a 55 gallon. They probably would not venture down to the bottom to bother the cories, but it would be more ideal to get about 5 more danios to avoid them getting stressed.

 

Dioman tetra are small and the school should be fine in a 20 gallon. I suggest that you move the danios to the 55 gallon at the same time. Danios are super active and they will use the entire 48 inches of a 55 gallon. They probably would not venture down to the bottom to bother the cories, but it would be more ideal to get about 5 more danios to avoid them getting stressed.

Hello everyone. I bought 6 diamond tetras a few weeks ago to put in my 55 gallon tank with cories, rummy nose, and a honey Gourami. They are very aggressive with food, to the point where they steal all of my cories wafers when lights are off. And when the cories are on them, they butt them out of the way to snatch them up. I don’t like fish messing with my cories at all. I have a 20 gallon with 5 zebra Danios and 8 neons, would this be a better set up? I kinda feel bad moving them to a smaller tank, but they do not leave any food for my other fish, and are aggressive to my cories. What do you think I should do?

The danios will most definitely go to the bottom for food. Greedy, zippy little brats. Lol. But I agree, they would love the 55. That's what I have mine in.

In my experience they don't hurt the corydoras though, they just eat. And eat. And eat. And eat.... Someday, I imagine mine will eat till they burst, but I've given up trying to avoid over feeding them. I put in enough sinking food that the corydoras all eat their fill. I feed the danios at the same time, either flake, or thawed frozen food that swirls around in the current. Even when a danio nudges a cory from one bit of food, the cory just calmly keeps eating or moves to a different piece of food. The danios aren't mean, just pushy. I had a gourami I had to get rid of cuz he screwed with my corys too much though.

The thawed frozen food, especially small stuff like daphnia, blows around and settles everywhere. Even if that was all I fed and the danios ate every bit they saw, there is no way they could find it all. Plenty left in all the nooks and crannies for other fish. They don't seek it out all day and night the way corydoras do, they just gorge on any they happen to see.

That said, I think the 20 ought to be fine with or without the danios. Just keep an eye on your parameters, like other said, in case anything spikes while the bb colony grows to catch up with the increase in ammonia supply. One thing I like to do when I plan on adding to a tank is to increase the amount I feed ahead of time. Spend about a week gradually feeding a little bit more each day. By the time you put the new fish in, their will be almost enough bb to keep everything in balanced. Much less likely to have any dangerous spikes that way.