Adding New Fish

[Danio8]

I have a cycled 10 gallon tank that currently has 1 honey gourami. I am planning to add 6 ember tetras as well. Is it ok to add all 6 tetras at once or should I add 3 at once, wait a week, and then add the other three? I would prefer to add them all at once but if that would overload the bio load that would be bad.

 

[Aiken Drum]

The new fish will cause some ammonia and nitrite in your water. The more fish you add the more ammonia and nitrite will be in your water. Add 1 fish the amount will be so low you probably wont see any difference, add 2 or 3 you might see low levels for a couple of days until your cycle catches up. Add all 6 and you might need to do a precautionary water change or 2 to keep water parameters safe and it might take a week for your cycle to catch up.

Generally speaking adding no more than 30% bioload at once is recommended, which would probably be 2 or 3 fish in your circumstance. But if you do a daily water test and change water if needed to keep water safe if the test shows anything elevated it shouldn't be a problem.

It all depends on how risk averse you are.

 

[Andy Sager]

I have a cycled 10 gallon tank that currently has 1 honey gourami. I am planning to add 6 ember tetras as well. Is it ok to add all 6 tetras at once or should I add 3 at once, wait a week, and then add the other three? I would prefer to add them all at once but if that would overload the bio load that would be bad.

You have a bit of a catch-22 here. It's better to add a school of Tetras so that you get ones that are the same size ( which will better help them survive together) but in a newish tank or a tank with a low bioload, you risk the ammonia spikes. You do have a couple of options tho: As Aiken mentioned, testing daily so that you can catch any spikes before they get drastic and doing water changes can help keep things safer. Once established, nitrifying bacteria reproduce quickly so the levels should decrease relatively quickly ( based on just how much added ammonia is present). Another option is to add extra filter material from an established running tank so that you are adding more nitrifying bacteria as you add new fish. A third option ( if option #2 isn't possible) is to add a product like Fritzyme #7 or Fritz Turbo 700 which are live nitrifying bacteria so you are adding the bacteria to counter any excess ammonia. Beware tho, there are a lot of products out there that claim to be live bacteria but many of them do not actually work. I have experience with the #7 and Fritz in general so I know it works. ( Always check the use by dates on the bottles because they have only have a 6 month shelf life. )

 

[Colin_T]

Add them all at once. Tetras need to be in groups and there is less risk of disease if you get one batch of fish compared to several batches.

 

[Danio8]

Thanks! I was planning to do Andy’s method of adding them all at once will a little bacteria from a cycled tank