Adding New Fish - how many?

[stooker]

As I continue setting up my community tank, I think I've decided on 8-10 celestial pearl danios to complete the stock. The issue is that I have to drive over an hour to the nearest LFS that has them in stock. Preferably, I'd like to get them all at once so I'm not driving back and forth several times with my 3 year old in tow, but also don't want to introduce too much bioload all at once. With my current setup, how many do you think I should get at one time? Tank is fuly cycled and the last time I added new stock was several weeks ago.

20 gallon high
Eheim Classic 2215
Also running purigen in the filter
6 Peppered Cory
2 Dwarf Gourami
Low tech/low light, moderately planted

The danios will be small, so that's a plus, but 8-10 is more than a handful. I can definitely increase the frequency and/or percentage of water changes as required. Thanks in advance for any good advice!

(and yes, people have mentioned the two gourami, but they are so far doing well with the plants and hardscape available to them. They have small tiffs here and there but one is not bullying the other)

 

[friscuba]

Not that I have any evidence to back it up, but I like to try to do no more than double the bio-mass/load at any one time. I've pushed that on occasion. In theory the nitrifying bacteria in your tank can double (or more) their numbers in a day if conditions are good, so all things equal doubling the load is quite doable, especially if you feed light for a day or two. It seems to me that as long as your tank's in good shape as far as water changes and quality, you won't be overloading it with what you propose.

 

[stooker]

Not that I have any evidence to back it up, but I like to try to do no more than double the bio-mass/load at any one time. I've pushed that on occasion. In theory the nitrifying bacteria in your tank can double (or more) their numbers in a day if conditions are good, so all things equal doubling the load is quite doable, especially if you feed light for a day or two. It seems to me that as long as your tank's in good shape as far as water changes and quality, you won't be overloading it with what you propose.

Got it. I was already planning on reducing the amount of food for a few days regardless how many I add. I'll also do a WC the day before I get any new stock.

 

[ScotJudd]

You will probably be Ok because you are aware of the possible initial overloading problem. Regular water checks and, as you say, WCs where required will let your filters catch up with the extra bio load.
The problem really comes when a fish keeper doesn't understand the implications of adding extra loading.
Good luck with the purchase.


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