1st time questions!

[xxxmemxxx]

Hi i wud like to ask a few questions hope someone out there can help me!

Firstly i would like to know if it really is normal for the top of the soil to go a bit white and look a bit mouldy i know this sounds like a silly question but my friend has told me that this is perfectly normal as it is just a sign that the nutrients are being used up in the soil from the plant, but i have my doubts.

Secondly i have heard that using an ultravoilet light is a good idea and can help the plant but also to much use can burn the plant so i was wondering if it is okay to use and if so at which stage should i use it and shud i only use it for a certain ammount of time each day.
Hope some nice person out there can help me i really wanna get this right!
thanks
x >>>>>>>>

 

[Akornpatch]

It should look like dry dirt...not moldy. Your friend is leading you a bit astray with the "used up nutirents" comment. Does it go back to black when you water? Does it look fuzzy at all?

All light has UV of some kind...what specifically is the light source?