Hard water means GH is high. I have extremely hard water (KH = 15 and GH = 24). They love hard water. Typically, water softeners make the water softer (well duuuhh) and adjusts the GH parameter that cichlids love. A good way to tell if you have hard water in general is the white caked on powdery stuff in bathroonms and on the top rim of your tank. But a test kit for GH and KH will tell you the whole story for sure.
Labs and zebras are from lake malawi (i think - neway, the same lake) and will get along well - I have these two types of cichlids.
Identification (I can be wrong on all of these btw)
Pic 1 = Albino Zebra - hard to tell from pic
Pic 2 = Texan - maybe - head does not look right for texan though.
Pic 3 = Blue zebra
Pic 4 = hard to tell - what does the tail look like?
Pic 5 = Aratus Cichlid (maybe a sunset cichlid??)
Pic 6 = Orange(Red) Zebra
Pic 7 = I dont know
Pic 8 = I dont know
Pic 9 = could be B.B Ornatus Cichlid
PIC 10 = Yellow lab (you are correct)
I dont know exactly if I am correct - these are merely a starting point for you.
#2 is a Geophagus species, comes from Soft acidic water in the amazon region, and not compatible with the other fish. All the others appear to be species from Lake Malawi, which need Hard Alkaline water, pH above 7.8 and a gH of 10 or higher, while the geo would thrive in water with a pH of 7.2 or lower and a gH closer to 3. Remove the Geos and the tank provided you have enough space, should be fine. You will have aggression between the Malawis but its quite common.
the first is an albino zebra. theres an aratus mixed in there for sure the last 1 is not a labedochromis. Its way to dosile to be kept with the others. Also theres no dorsal stripe. My guess is a female johanni.