Adding schooling fish to a new aquarium - a few at a time?

[ViviChu]

I see recommendations to add only one or a few fish to a new aquarium because the cycling may still be going on, but also when adding schooling fish it's recommended to add at least 6, preferably more.

I have a 17 gallon planted tank that I've set up almost 2 weeks ago. Some of the plants melted at first, but are now coming back and growing really well. I wasn't adding ammonia, because I figured the decaying plants would serve that purpose. There are also bladder snails and they are growing and multiplying.

I've done one water change so far of maybe 10%. My test strip gave me these results a couple of hours after:

• NO3 - 10-25 mg/l
• NO2 - 1
• GH - 4 degrees
• KH - 20 degrees
• pH - 8
• Cl2 - 0

I'm going to add some minerals before I add fish to raise GH. Should I be doing anything else?

I would like to keep glowlight danios or white clouds. When and how should I add them to the tank? Do I wait another 4-6 weeks and then add them all at once?

[Ben Ellison]

I normally add them in sets of three and I find it doesn't bother them much. I think a couple few weeks it isnt a issue for schooling fish.

[Mitch_ScruffyCityAquatics]

I agree with Ben on a new tank or smaller tank. I always did the three at a time method. It kept me from having to chase parameters and no spikes when adding young fish. 
 

if you have a larger tank or when your tank becomes seasoned (months of everything going groovy) you can add more at a time. I once added seven young neons to my 75 gallon with no major change in parameters. I’m sure it changed something, but so didn’t see it. 

[Dandy Pearl]

I agree with all previous posts, except that the tank is only 2 weeks old. If you want to add fish, only add the first 3pk and wait at least a month before adding any more.

Since the tank is new, it is not well seasoned at this point. Adding a few fish will help with the seasoning process, but only add a few at this time. You don't want to add a bunch of fish, get an ammonia spike only to kill them all.

Starting a new tank is fun and exciting! But, go slow and you will likely be more successful.

Watch Cory's videos, learn, have fun, repeat.

Good Luck! 

[ViviChu]

Thanks everyone! I went to the store (another city, long drive, went there on another errand), and they didn't have glowlight danios nor white clouds, but they had two leftover CPD's so I got them both. I'll be making another trip in two weeks. Should I get one or two more then (if they have them) or just wait for a while until the tank gets more established?

[Andy's Fish Den]

9 hours ago, ViviChu said:

Thanks everyone! I went to the store (another city, long drive, went there on another errand), and they didn't have glowlight danios nor white clouds, but they had two leftover CPD's so I got them both. I'll be making another trip in two weeks. Should I get one or two more then (if they have them) or just wait for a while until the tank gets more established?

As long as the first two that you got are doing good, no signs of illness, I would say you should be good to add a few more of them. 

[Mitch_ScruffyCityAquatics]

15 hours ago, Dandy Pearl said:

I agree with all previous posts, except that the tank is only 2 weeks old. If you want to add fish, only add the first 3pk and wait at least a month before adding any more.

Great point! I totally read that as 2 months for some reason. 
 

Slow and steady will provide the best outcome. It is hard not to buy all of the inhabitants you want, but you will have a better experience if you let the tank keep up with the bioload. 

[ViviChu]

It's been almost two weeks. The two CPD's are doing great. They were shy in the beginning, staying mostly in the corner under the HOB filter, but I see them going out and exploring the rest of the tank more now, I think they are both males. 

On October 17, I had NO3 of 50 mg/l and NO2 of 3 mg/l.
On October 18, NO3 dropped to 25 mg/l and NO2 stayed at 3 mg/l. I topped off the aquarium with some bottled spring water. 
On October 21, NO3 was 25 mg/l and NO2 was 1 mg/l. I changed about 25% with tap water treated with Seachem Prime. Water was tested before changing. 
On October 22, NO3 was 20 mg/l and NO2 was 1 mg/l. 

I tested again today and NO3 and NO2 are both at 0 mg/l. I tested ammonia throughout and it was always at 0.

Does this mean my tank is cycled? It was started on October 1st with a lot of plants (which likely had some bacteria on them, along with bladder snails) which are growing really well now after some of the original leaves melted.

Can I add more fish? If I can't find more CPD's since they seem to be pretty rare here, would adding some other type of Danio help the first two feel less lonely? Or some white clouds? 

Thanks!
 

Edited October 26, 2020 by ViviChu
Fixed the typo in numbers and clarified when the water was changed.

[Ben Ellison]

I would say your tank is cycled now. Can you special order more of the CPD? They will really prefer to have more of their own kind. They won't school with other types to my knowledge. 

[Mitch_ScruffyCityAquatics]

You want 0 Ammonia and NO2, but to be cycled and starting to “season” you want to see some nitrates. Did you just do a water change? Some nitrates means your cycle is working. If it were me I would wait to see that I am regularly producing nitrates, but sounds like it is going well!

[ViviChu]

1 hour ago, Mitch Norton said:

You want 0 Ammonia and NO2, but to be cycled and starting to “season” you want to see some nitrates. Did you just do a water change? Some nitrates means your cycle is working. If it were me I would wait to see that I am regularly producing nitrates, but sounds like it is going well!

This was tested after the lights were on for a few hours. Could it be that the plants used up all of the available nitrates? It's been 5 days since the last water change and the nitrates went down on their own since then. 

[Mitch_ScruffyCityAquatics]

Plants could have used the available nitrates. Are you dosing any fertilizers? Sounds like you may be a go for adding fish. I would just go slowly to make sure your bacterial colony can keep up. Plants make life a lot easier. 

[ViviChu]

No fertilizer, but I have an inch of garden soil under an inch of gravel for the substrate.

I'll add 2-3 more fish and keep testing to make sure it's all going well.

[Streetwise]

Your setup sounds good. The garden soil gave you a head start.

[Ben Ellison]

I think testing 0 in nitrates simply means you are using all of it up in plant growth which means you aren't getting max growth but that isnt a bad thing. I would think ideally if you was to run ur light 8 hours running out 7 or so hours in would be the most ideal balance. For me as a pure blooded American I tend to force feed my plants about 10,000 % the needed nutrients 🤣 so my nitrates stay high. Like stupid high 😉 

Edited October 27, 2020 by Ben Ellison

[ViviChu]

They didn't have any more CPD's, but they said they should get them in 2-3 weeks. Instead I got more plants and 3 platies. Both of the females gave birth a couple of days apart, so now I have a lot of babies hiding in the plants. The CPD's were super shy and didn't even come out to eat much for the first two weeks while they were alone. But since the platies came, they've been much more lively, staying out in the open, swimming around, chasing food. Even their color improved dramatically. They were almost transparent when I got them, but now it's easy to see the lovely pearl pattern.

I'll add 4-6 more CPD's and I think that'll be that for my tank. I'll let it all grow and settle.