And if you decide to 'fishy' cycle then
Ammonia: should be 0 at the end but when you add the first fish in fishy cycling will go up. Anything over 0.5ppm is nasty for fish and means doing some water changes if poss to reduce.
NitITE: should be 0 but again will spike during the cycle. Is ~ half as toxic as ammonia so can be up to 1ppm while cycling. Again if over that do some water changes.
nitrATE: should be ideally less then say 25ppm, never over 50ppm - check your tap water as some start out really high!
For all the above lower is better
I found Hagen's 'Cycle' product really helped kick things along and would recommend it unless you are really hard up for cash. Personally I did fishy cycle - and nothing went horribly wrong, although I did spend quite a while water changing when the nitite peaked. Its up to you - I haven't tried the other way yet so have no comment!
As to general water profile for african cichlids (judging from net only - I don't have any of these - feel free to correct - experts!)
P.H.: 7.5-8.5
G.h: 7
K.H: 10-12
However Red tailed Sharks aren't african chiclids are they?? I thought they were asian? Don't know a good cichlid site I'm afarid...
Finally - as for water purifier - it shouldn't make a lethal difference although it may harden your water (lower KH I thiiiihnk) as it removes salts?? To be honest I think you should just check the water before and after purification with your test kits and see for yourself
You need a test kit for everything in
bold above btw, or a multi-test strip might cover most of them. You'll also need a dechlorinating solution to treat tap water (purifier or not) - but I guess you know that already right?
Apologies in advance for errors - written in a hurry before leaving work! Hope it helps make things clearer for you!
aj xx