# Pencil fish & Rainbows.  Are they compatible in a community tank ?



## mrtom (20 Nov 2013)

Pencil fish & Rainbows. Are they compatible in a community tank ?

My Set up: 180 L Rio tank
Current fish stock:
3 Swordtail
5 Pencil Fish
8 Cardinal tetra
5 Green tiger barbs
7 Rummynose
1Albino Bristlenose

I added 5 rainbow fish to my 180 L Rio tank some 10 days ago.
Melanotaenia boesemani x2
Melanotaenia praecox x1
Melanotaenia lacustris x2

I have noticed a behaviour change with the Cardinals and the Pencils since I added the Rainbows:
The Cardinals now stay in a deeper planted area and the Pencils gather in a group.
My question is will this behaviour change over time as they get accustomed to the new additions and may they revert to exploring the full tank as they used to?
Or do I return the Rainbows to the shop to restore peace and calm?
Videos to illustrate behaviour


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## Michael W (20 Nov 2013)

I doubt the bahaviour will change, its likely that the sizes of the rainbows intimidate the smaller tetras. Rainbows swim quite fast too so that may add to the intimidation. Also, rainbows prefer to be in groups mixing different types of rainbows won't have the same affect as having a group of one species, likewise with tetras. Shoaling behaviour is usually stress related I have Rummynoses with my angelfish and they will often shoal due to the angels' presence but they don't hide.

Instead of having the rainbows maybe you can trade them back in and add more to those tetras/barbs.


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## sanj (20 Nov 2013)

I cant see any M.lacustris in there, but I do see M.parkinsoni.

M.parkinsoni and the boesemani get quite large, they are generally peaceful, but males can squabble a bit. I would say that a 180 is on the lower end for living space for them. Personally I would not choose them with pencil fish, but then you also have very active Tiger barbs. If you do want melanotaenia rainbowfish then upping the number of M.praecox to around six would be a better move, they also stay around 2" or so.

Otherwise you could look at blue-eyes, Furcatas for example.


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## DTL (20 Nov 2013)

I've got a dozen dwarf pencils in with around ten dwarf rainbows. The pencils seem oblivious to the rainbows and definitely do not school in response.


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## Michael W (20 Nov 2013)

The thing is, having large numbers of schooling fish can lessen their stress providing there is adequate cover from plants too will help. The OP only has 5 pencils and in my opinion that is a relatively low number, in fact even 8 cardinals are low depending on tank size, safety in numbers.
Feather Fin rainbows are pretty darn good and are relatively small compared to the others so that may also be a suitable alternative which may not cause as much stress to the tetras etc.

If it was me I'd lower the number of types of schooling fish and concentrate on maybe one or two of them. I tend to have one type of mid water schooling fish and some bottom dwellers usually corydoras in my tanks. You could perhaps have a centre piece fish like a dwarf cichlid.


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## sanj (20 Nov 2013)

> If it was me I'd lower the number of types of schooling fish and concentrate on maybe one or two of them. I tend to have one type of mid water schooling fish and some bottom dwellers usually corydoras in my tanks. You could perhaps have a centre piece fish like a dwarf cichlid.


 
Same here, but looking at the current stocking, it reminds me of my early days in the tropical fish hobby, i dont know if the op has been keeping fish for more than a few years or not, but it can be hard given the variety of tempting fish available to keep to a few species when there are so many. Generally I would agree aesthetically and in terms of fish well being, it is probably better to have fewer species and larger numbers of them.


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## mrtom (20 Nov 2013)

Sound advice; time for the Rainbows to return and maybe a couple more of Pencils & Swordtails for stability and harmony!
Odd that there was no such reaction from the Pencils when the Tigers joined the community several months ago.
Now the interesting job of netting in a planted tank.


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## mrtom (29 Nov 2013)

Thank you all for your helpfull advice!


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