HQI Metal Halide or High Pressure Sodium (HPS)

[ReeferDude]

I have always wondered why HPS is not recommended for saltwater cause i work a huge nursery and in our greenhouses we run Both MH and HPS but ive noticed on out light meeters that the HPS burns brighter than the Mh and its more of a purple blueish tint. Does any one know why HPS is not recommemded

 

[dz6t]

HPS has the wrong color spectrum for coral I heard. May be I am wrong.

 

[JohnK]

Yup, HPS ='s very yellow.

 

[naturebatslast]

But, dual use ballasts are made to fire MH or HPS bulbs, mogul of course. But agreed, HPS bulbs are too yellow of a spectrum for reef MH lighting. HQI are awesome bulbs and ballast, but have some drawbacks like overdriving a bulb - you get more light (which is good) but you use more electricity and bulbs have a shrter lifespan. Some say the bulbs are tricky to get out every now and then, that alone made me choose mogul/single ended(SE). Another option is a electronic ballast.

 

[maurod]

I am fairly sure you can use a 400W HPS ballast to fire a MH bulb.

 

[RichConley]

I am fairly sure you can use a 400W HPS ballast to fire a MH bulb.

IIRC, 400w HQI MH ballasts ARE 400w HPS ballasts.

 

[JohnK]

Actually 430W,

Why there are 400W and 430W ballasts is beyond me, but that's how it is?

 

[dz6t]

There were a disscussion on RC to use HPS ballast to fire HQI bulbs. Actually, the real value of a MH is more on the quality of the bulbs and reflector/pendant design. MH ballast is not very expensive to begin with.