1)- the tank is 48x18x24, should i be considering using 1 or 2 heaters & appropriate wattage ? ... 4-5 watts per gallon ?
Two heaters is usually best, so you have a backup in case one of them gets "stuck" on or stops heating altogether. I think the general recommendation is 50W per 10gal, but I have a 50W heating about 20gal of water right now and it seems to do fine
2)- ive read some people using "pool filer sand" as the substrate, is there an advantage ?
Pool filter sand is smooth grains of silica sand. As such, it's inert (won't change your water chemistry), and the smooth grains are easy on delicate barbels. I think you can get it in slightly different colors, but the stuff I have is a very bright off-white that gets tan as stuff grows on it. So, it depends on what you're looking for. If you're going something that looks very natural, don't get pool filter sand. However, it is very cheap. I got a 50lb bag for a little less than $30. If you want a more natural look, you can go with play sand, meant for kids' sand pits. It's a little "dirtier" than pool filter sand, but usually even cheaper and it has a more natural appearance.
3)- since i'm considering Cichlids, should i use crushed coral as my substrate ?
Depends on the kind of cichlids. If you're thinking of getting rift lake cichlids, then yes, you might want to consider crushed coral. I know there are also products sold that get water up to the insanely high GH that some of them need. I think crushed coral would only get you so far
4)- our water here has both chlorine and chloramine in it, my local fish shop has recommended a couple of dechlorinator products, will a dechlorinator remove the benaficial bacterie ?
No, dechlorinators won't do anything to your bacteria. If they did, we'd basically never have cycled tanks! Or our living spaces would just be filled with buckets of aging water. But do note that you will HAVE to use dechlorinator. Chloramines don't evaporate from water like normal chlorine does. You can also use Prime by itself, just at a higher dose (it has instructions for chloramines).
5)- for cycling process , i'm planning to start with Dr Tims Ammonium Chloride to get the process started, reviews on line are pretty good, thoughts - opinions ?
I've never used it, but I hear good things. You can also just go to the hardware store to get ammonia. It's the same thing and it'll be much cheaper than getting ammonia marketed for aquariums. Just make sure that it has NO additives. Surfactants are common additives in ammonia-based cleaners, so make sure you're getting pure stuff
