Question On Stocking Issues

[BaylorPerez]

As i have a 55Gal tank with a 80Gal filter. I was wondering since i have 5 Rift Valley Cichlids, 1 Clown Loach ( soon to be moved into a 100G tank ) and 1 Common Pleco( 6"  so far ) what would be the best amount of cichlids to be put into the tank. As ive been told by my LFS 7 is enough, another said 15 would be the max and another said 2 would be best. 
 
On the Confusion i asked why so little for the 2. They said there wouldnt be any aggression.
The 7 said more spread out aggression
the 15 said Spread out aggression to LIttle to no territorys in the tank. As well as there will be fish deaths but the fish would find out the best amount for the tank itself ( i dont want to pay 150+ $ to be losing 70$ worth of fish ).
 
Now to the other parts. Plecos and Cichlids are ok, but what other species could i house with these 5 Cichlids. I was thinking of buying some Giant Danios. But i am unsure so thats why im asking here

 

[NickAu]

 
Rift Valley Cichlids,

Dont these prefer high ph and hard water?
 

 
1 Clown Loach

While these want soft water.
 
 
What sort of water do you have? Soft or Hard?
 

 
what would be the best amount of cichlids to be put into the tank.

That would depend on what type of fish they are, A 55 gallon may be fine for say 10 of a small fish yet may be too small for 1 or 2 big fish.

 

[BaylorPerez]

my water is soft. Great for some cichlids and great for loaches. As how many cichlids would be great for a 55G tank. 5 at Currently 4" per fish along with a 4" loach, and a 6' Pleco