Stocking question

[Phil22]

I have a 20G with a single Penguin 150 filter. I have one Johanni (about 2")and a bright orange one - from my brief research this one appears similar to a Red Zebra Cichlid, but has a few black markings It's about 3 1/2 - 4".
They have been living together pretty peacefully for about a year and a half now...the orange one definitely more dominant (and quite the tank redecorator).
I'd like to get one more...perhaps an electric yellow. Would you recommend this given the size of the tank? Or should I just leave well enough alone?
Thanks.

 

[MikenDanielle]

I would have to say you would be ok with adding one more. From what I have heard a general rule of thumb is 1" of fish per gallon of water... allowing you to have 20" total. Of course you have to use the fishes expected full gorwn lenght for this, but the two you have and the Electric Yellow may put you an inch or two over but I can't see it being too much of a big deal. You should post some pics!

 

[Coler]

well, ignore the inch per gallon rule.

generally with rift lake cichlids you want to overstock a little bit to cut down on aggression, or have a truly big tank to observe natural behaviour.

thing about a 20 is that its not really big enough for a mix of mbuna. Also, you've had yours for a year and a half and I'm guessing that your 2 fish have pretty much carved up the territory and will be greatly hostile to newcomers, and are a fair size. I don't know of a suitable mix of numbers ( 'specially considering size) to add that would reduce the risk of WWIII in there to make it worthwhile to try.

If you try adding a couple drastically re-arrange to decorations in the tank t disconcert the 2 fish already in there and if you havn't already, create lots of caves.

Labidochromis careulus are generally amongst the most placid mbuna and prefer to be in groups. I'd be concerned that they would not be able to stand up for themselves against the 2 fish in there already.

I wonder if the best of some poor options would be adding some (perhaps 2 or 3) females of one of your fish types (you would appear to have males)? Perhaps somebody more experienced would comment.

Any chance of an upgrade on the tank size ? Would really increase your options