Well that depends on what size tank. For instance 20g=2(1 of each or 2 of the same). labidochromis caeruleus can attain a size of up to 8" where as the Pseudotropheus saulosi(i think thats what you mean by salousi) only reach a max size of about 3".Based on the max sizes of these Mbuna cichlids you will need atleast a 20/30g or bigger to comfortably house them,with lots of rocks/caves/places to hide.

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My Giant Gourami has a gun and refuses to take his meds.

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http://www.youtube.com/watch?v=dyOK8Ymd9l8