Help, Lighting positioning!

[Slickcg33]

I currently have a Solana Aquarium. The dimensions of the tank are 20x20x20 and its 34gal. For those of you who are unfamiliar with it, you can reference it here...

Solana - Aquarium System | Current What's Next

I just purchased the Aqua medic ocean light pendant for the tank. its 250w mh 20k.
It can be found here for a reference....
Ocean Light Pendants HQI - Aqua Medic

My questions are as follows;
1.)How high above the water in inches should I position the light so that it doesn't create too much heat and
2.)so that it doesn't bleaching anything being too close?

Any input or advice is much appreciated, thanks!

 

[Dentoid]

You will want to start the light fixture above where you want it to eventually end up hanging to acclimate your corals to the new light. Start it out high, then slowly move it closer to the water, over a period of a few weeks, until it's about 10"-12" from the surface of the water. You can move it closer if that's not enough.

 

[Slickcg33]

To start, what hight above my target end hight would you suggest?

 

[framerguy]

Start between 16-20". If making the height adjustable is not an option then you can use four or five layers of vinyl screen and remove one layer each week until the corals are acclimated to the light. With MH lighting you will probably need to add a fan blowing across the top of the tank to dissipate the heat.

 

[Slickcg33]

It will probably be difficult to keep adjusting it, so that's great advice, thank you!