Too much or Too little light - Corals

[RaymondL]

Without a PAR meter it's difficult to say how much or too little is for each different type of coral - I don't have the budget to purchase one at the moment, and nobody I know in my area has one.

As a gauge is it safe to assume that if there is too much light ALL corals will appear retracted - not open up? Likewise, too less light the corals will open, but some might look stretched as they reach for more light?

 

[tbrown]

It's going to be different for every coral. Typically though, too much light will cause corals to retract and start turning white as they expel "excess" zooanthelle (sp?) while too little light will cause them to start browning out. Certain corals will reach for the light bulb some corals do that when they're happy in general and not from a lack of light.

 

[Mr. Mojo Rising]

If you mention your type of light and tank, it is likely that someone here has a similar set-up and will be able to offer guidance for the intensity/duration.