causes of bleaching

[skaterzero22]

im still young and just now beginning to study marine biology at the college level. had a few years in high school and am curious to know what is the cause of bleaching in house aquariums. i know that the bleaching in the wild is happening because of growing climate temperatures but i always see people saying "that is too much light for that aquarium" is the amount of light going to affect anything in the tank or is just the temperature the light will give off? if a 60g tank can use 2 250w MH than why is it said to be too much on a 55? etc etc

 

[BLKTANG]

When bleaching happens in our tiny reef aquairums,it mostly (90%) is due to not properly acclimating corals to the type of light we have.IE: your LFS carries a green branching Hammer coral in a prop tank under VHO's,then you take it home,& put it 5" under a 250w MH bulb.

I had a nano some time ago 29g,& had 2 150w 14k Phoenix bulbs,& never burnt (bleached) a coral.I think that in most cases its just knowing what conditions the coral that you intend on purchasing came from,& properly acclimating the coral to your conditions.

 

[skaterzero22]

hmm good to know.. a lot of people frowned upon me having 2 250's over my 55 and the temp in the display tank hasn't hit 80 yet. so if the actual lighting isnt to strong than i shouldnt have to worry about bleaching.