New LED questions

[JWHITESP88]

Hey guys, I want to start by saying what a great group of people here. This will be the second thread for myself and had wonderful replies full of great information on the first one. I have been around the hobby for about a year now but have only gone reef but have regretted not going saltwater from the beginning. Enough about all of that I have some questions about some lights that I bought.

I have a 40b. With a lot of research and advice from members of another forum I decided to buy some Tao Tronics
http://www.amazon.com/gp/product/B0092LXQRM/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
I bought two of these fixtures and hung them about 8 inches off of the tank. My question is do you think that this is to much light and do you think that these are good quality lights or did I mess up? Would I be able to get away with just one fixture? I just want to grow some softies and sps. I know this sounds weird but they kind of intimidate me, it's alot of light. I guess what brings me to ask this question is the last two days little brown hair looking algae has started to grown on the black glass and sand bed and Im not sure if its to much light or not. I have been reading and some say that this is common after diatoms have come and gone (8 weeks old). I just want to make sure that the lights are not overkill on the tank and how you guys would run them? Sorry this is so wordy just a new guy trying to figure some lights out. Thanks for all of your help.

 

[mrBananas]

Having two units will give you a better coverage, so fewer areas in the shadows. You can probably get away with one fixture, but the edges would likely be in shadows depending on your rockscape. If those units are dimmable, you could always turn down the intensity and slowly bring it up to acclimate corals. If they get too bright, you'll begin to notice warning signs such as fading/bleaching and little/no poly extension.

 

[KoleTang]

You would be getting some bad shadows on the sides of your tank if you had only one LED panel over a 3' tank.

LEDs are more powerful than you may think, so be careful when acclimating the corals.

 

[JWHITESP88]

Thank Tang. I have not ventured into corals very much yet. I do have a couple of Zoa's that made there way to my tank on a live rock that I purchased. Is the hair algae normal at this stage of the tank or could this be something I am fueling with the lights?