coral question

[wjake]

I just purchased a maxspect razor 120 watt and am new to reef aquariums. How do you know when your corals have too much or too little light. The ones in the store are almost all actinic all day long which I suspect are make the color of the corals stand out in so folks will purchase them.. It is beyond blue in color all day long

What would be a good % to start with to keep from either bleaching the coral with too much light or killing them with not enough? How long do the lights need to be on and how much spread of blue and white (I can control both channels)

It is going on a nano aquarium that is 29 gallons and 16" deep

 

[ringo®]

Best thing you can do is rent a PAR meter. Any number somebody gives you is going to be a educated guess at best.

 

[hnguyen]

Par on LED's are totally different from PAR on T-5's and metal halide. I would start out at around 50%-60% and wait a few or two before making adjustments. I made the mistake of relaying on a PAR meter when I had my AI Vega and burned a lot of my corals. I was barely getting 200 PAR right at the top of the tank beneath the lights running at 100%. So instead of leaving it at my normal 70% where my corals looked happy, I left it at 100% and a few weeks later all my corals looked like crap and some started to die.

If your corals have too little light, they will tend to extend their tentacles or polyps out further to try and receive more lights. Too much light and they will burn and start to lose color. With SPS, I've notice too much light = bleach white and too little light = no color but not bleach white, not until their dead. Too much lights for LPS and they tend to bleach as well but their tentcales or polyps look more retracted instead of extended.

Please note this is just from my personal experiense and that you should do a little more research on your own before taking my word for it.

 

[jc_k]

I started at 50% and gradually raised it to 70% on my mixed reef. I guess it kind of depends on what coral you have.