Tao Tronics LED lighting question for my 29g nano

So I purchased one of these made in china Tao Tronics 120W TT-AL12 lights, although mine is a no-name but exactly the same. My main question is how high off the water (open top tank) to I hang this fixture. Currently I have it hanging from the ceiling at 16" from top of water surface. Also, what Blue and white settings should I use or do you recommend. So far I have had a horrible experience in that I was told by somebody to just place the lamp on a glass lid (had the glass from another tank) and keep at current factory settings (55 3W 12K). BIG mistake in that it fried my tank the first day, including Xenia Frag and hammer frag. Trying to get hammer back from the dead. After that experience I went on line and watched a few You tube videos on this system and have adjusted 24 hour cycle to very low amounts with emphasis on blues. Got home and there seems to have been a diatom bloom in just one day. But still lamp is hanging at about 16" above water. HELP!

 

You will need to light acclimate. That fixture is overkill so you will need to dim it significantly.

 

Any recommendations?

 

Well I would start at 20/20 probably. Just for reference I ran 1 of those fixtures for 2 years on a 90 with lps/clams on the SB.the fixture was approximately 8 inches above the waterline.