African Cichlid Question

big is always better...you can go on the basis of trying to give each fish enough space for a territory but that's frankly unrealistic for most people. So with African's you're often going to overstock instead, in order to prevent the fish from claiming too large a territory, or claiming one at all.

I would say you want a 55 gallon tank and the longer the better, with lots of rockwork.

depends on the filtration, decor, how much maintenance you're willing to undertake and, most importantly the species mix, the individual fish and the gender mix.

30 is probably pushing a lot of parameters in a 55 pretty far. Around 12 - 15 is more realistic.

http://www.cichlid-forum.com/articles/quick_reference_list.php here's a link to some stuff including a cookie cutter type suggested stocking reference

edit : I was reading your q as asking how many fish as opposed to species...species wise you might mix 3 species in a 55 if you're doing a mix of species and not e.g. an all male tank in which case you don't mix species and try and avoid similar colourations

also, you're likely never going to cut out all the aggression - that's just in the fish. It's a question of management.

Eventually, you would need at least a 55g, but when they are younger, you can 'grow' them in a smaller tank if that's all you have, but if you have to buy a tank, go for at least a 55g, preferably a 75g!

This is just my opinion, but I would look at something other than the electric blue. There are so many cool malawi cichlids out there, and while this is a neat looking fish, I would opt for something a little more uncommon. I also see Blue, Orange and Blue/Redish... You're needing some yellow.

Otopharynx lithobates (Zimbawe) -cool blue with yellow 'top' instead of electric blue...

Placidochromis electra (Stunning) - just look them up..

Copadichromis azureus -Electric Blue II more peacful than what you're looking at...

Aulonocara stuartgranti (Rubescens) (Ruby Red) - Blue and Red/Orange... STRIKING!

Aulonocara stuartgranti (Usisya) (Fluvescent) - Blue and Yellow

Aulonocara sp. Lwanda - Purple and Yellow

Tramitichromis sp. "Intermedius" - Sort of an aqua/neon blue with red/blue fins
I also like the Taiwan reef, but they're in the same family as the Red Empress.

You could also keep say, a group of 5 red empress, and do all male with the rest.. or some sort of mix.... but it's your call! Just look at what's out there other than what's in your LFS!

OOPS! I see now that you're upgrading your 29g to a 55.
In THAT case, I would get a 75g... no reason to buy a 55 when you get a 75g.. trust me!

But I would save up now.. at their size, the 29g is fine, the OB Zebra will grow quick, but you've got a long while on the Empress and Blues... You'll know when it's time to make the jump.