first think...
how manage the water...

second....
the best ligthing...
for 3 1/2 fit tank...

third....
why the life coral die...

Let me chip in abit here.
1) Change water regularly. Best if weekly changes of 30% or more.
2) Best lighting is the brightest you can buy. Metal-halide bulbs. For 3.5' tank, use 2x150W or 1x250W. Warning: they run extremely hot.
3) I personally hv tried keeping corals, and believe its very-very hard to keep them alive for any length of time. Corals just cannot survive in a tank. We can only prolong their time to death.

Corals need these in order to survive:
1) Clean stable water.
2) Super-duper bright lighting.
3) Cold water temp at ave 24degC.
4) Supplements like calcium, iodine, etc...
5) Feeding with micro-organisms, eg. phyto-plankton.
Only go for corals if u can provide all these basic requirements. Dont go half-way, or try-try-see-see. Will only end-up with dead corals n empty pockets.

My advice is read-up and do ur homework before venturing into keeping corals. Its not easy, not cheap, n very time consuming.

Happy coral-ling

As CnT, it's better not to start on a marine tank and do things half-heartedly. This is not a system for you to try-try on, cos living things can and WILL die, if you don't know what you're doing.

I can't remember whether I posted my beginner's articles in here, but if I didn't, PM me and I'll pass you the links.

My only difference in opinion with CnT is in the choice of lighting. MHs are very nice lights but expensive, very hot, very expensive to maintain (high TNB bills) and generally not very efficient. They however can penetrate to the deepest of any lighting. But if you do not plan to have anything taller than a 2' tank, I'd suggest you take a look at HO-T5 lighting (high output T5) systems. They're cheaper, come with lots of colour combinations, are much less hot, and VERY efficient on electricity.

Corals are living organisms just like you and me, and that's why they can die !! But of cos, not looking after them well just makes them die a lot faster. Under ideal conditions in the sea, corals do NOT die, and just get bigger and/or mulitply into many colonies. This is what we try to achieve in our tanks too.

Just remember to do lots of research first before you buy anything (especially livestock). I know it's hard to resist jumping in ( I was like that 24 years ago when I started in marine too!), but try your best to resist until you know what you want, and what you need to do.

Cheers and good luck

first think...
how manage the water...
Thru test kit, make sure u got a very good salt wiv all the nutrients
Check PH, KH, NO2
Good filtration system - sumptank, canister or hang on filter replace the carbon filter wiv bio rings.

second....
the best ligthing...
for 3 1/2 fit tank...
For coral normally is metal hydrite but it will warm up the water, then T5

third....
why the life coral die...
Because no chiller, normally cost additional RM 900 - RM 1,200 with 6 mths or without warranty.

Well the cost to maintain a coral tank will be higher due to the fact of higher electricity consumption.

ok...
thanks bro...
other question...
why my live rock look coper color..

i need help from u...
if u want pic i can send to u....