Join Date: Jan 2012
Location: Hudson, Quebec, Canada
Correct on them both being from Lake Malawi.
Now, Demansoni, aggressive, territorial and yes will go after you, I had several and they would always go after my hand when I was python cleaning the tank.
Acei, nice, peaceful, usually enjoy swimming at the top of the water column.
Cichlids in general in the wild, live in a sandy, rocky bottom Lake Malawi, there are very few plants in the lake except where rivers join it.
As some have mentioned overstocking with good filtration is almost a must for cichlids, 55g being really the absolute minimum tank size at adulthood, this is for African Cichlids, some of the larger South American ones, 125g is minimum.
Rocks, rocks and more rocks, decorate the aquarium with yes rocks, or at least plenty of places to break up lines of sight so fishes can really see each other often. Part of the reason for a larger tank as this cannot be easily done in a smaller tank.
The issue with them going after one another is they look very similar to each other in terms of color, cichlids dont like each other very much.
Keeping a harem of 1 male to 4 female on most species, spreads the aggression from a single fish to multiple fish, unfortunately though, the Demansoni given it is very aggressive is in the super harem group of 1 male to at least 6-8 females.
They can be kept together with acei although I would not recommend it even when small in anything less than a 40g breeder, once the fish are 1.5-2" (inches), they start showing their adult traits, namely for the aggressive ones being a PITA. This is when you can safely keep them together for a bit, anything above this size and you HAVE to remove them if there is too much aggression and lip locking otherwise you will have dead fish.
Once you get the bigger tank size, then if you still want to keep them, perhaps we can offer suggestions as to stocking.
@Sena Convict and JD are compatible together, although the convict will be eaten/ killed if they are way smaller than the JD. JD is one of the most aggressive cichlids available in the hobby.
10g Fry / Hospital / QT tank (as needed)
75g Saltwater Reef, Ocellaris Clownfish, Lyretail Antias (baby), Lemon damsel, Longtail Fairy Wrasse, purple dottyback, snails, crabs and a few LPS corals.
220g Still sitting empty (come on Lottery I need the numbers to come up!)