Match made in heaven or WWIII?

[My Fish Frank]

I have 1 male betta (hm) in a 40L tank and I want some tank mates for him because k don't want to waste such a big tank on 1 small fish when I only have two tanks!

I am thinking of getting a few rummynose tetras, what do u think?

My hm is pretty placid (for a fighting fish), it takes a while to flare, and I used to have my 2 tanks side by side and he didn't try to attack my other fish in the other side.

[Oldfishlady]

In 40L(10gal) Rummy nose (Hemigrammus rhodostomus) This 2 inch long fish may be a tight fit along with the Betta...they really need to be kept in a fairly large school of at the very least 6...more the better or they tend to sulk and hide a lot and due to swimming needs...10gal will be cramped for them....They require good water quality and can be really sensitive to the slightest change-especially to additives and salt......they are a great indicator of water quality-since the red nose will fade in poor water quality...

This is a nice species of fish but would do better in a larger/longer aquarium with lots of live plants.....

[My Fish Frank]

yes but will they go with a betta? i can get a bigger tank if i need it.
my water quality is good and all the tests have come up perfectly fine

[Bombalurina]

To my knowledge, they should do ok a with a betta (not massively nippy), but I would try it in less than a 20long. Rummys are seriously active. That's another worry - their activity may stress the betta.
If you want tetras for a ten gallon, look at embers. They are perfect. In a 15, neons, black neons, green neons, cardinals...they are all good.

[Bombalurina]

Sorry, too used to speaking Americanese now. :p 15 gallons = 60 litres, 20 gallons = 80 litres (very roughly).