High pressure sodium lamps

[medicineman]

What do you say about the use of HPS (high pressure sodium) lamp in growing aquatic plant on combination with regular halide to even out the light colour? You know, HPS is another kind of HID lamp, quite similar to halide.

HPS is very rich in red and yellow spectrum and is yellowish in colour, so I can understand that some people might hate it. Green and especially blue spectrum and so on are almost none. Kelvin rating gets as high as 3000 and not more than that. Par and lumen is also great, recorded slightly higher or equal to regular halide. So I think this one is a very good, efficient source for growing plant that in fact it is widely used in plant culture industry.

I think HPS exist before the widespread introduction of cheaper and high K halides, some of you veteran or the plant culture folks might have experience on this type of lamp, I'll be happy to hear you testify

[kgbenson]

The hydroponics people use them whenever you are trying to favor floweing over vegatitive growth. Theya re more efficint than MH though. I would use them in conjunction with MH or the color rendereing will be very off.

Ketih

[medicineman]

Havent seen them yet so far on local hydrophonics (it is sunnly all year long around here). Perhaps the flower hydroculture industry use them regularly.

How about the effect to algae? I know algae can utilize a wide spectrum of light. I would guess just the same or even better control since all the available light is not out of what plants need.

Anyone tried them with great sucess to aquascape? care to share/testify?

[crazy loaches]

I am trying to setup my dream plant tank and was thinking about a MH HPS combo, however there seems to be little discussion on sodium lamps on the forums. MH usually lack the lower end spectrum but peak in the blues. Sodium is basically the opposite. They would seem to go together nicely. I only have a 4' tank though, and only need 2 lights and thought that one side MH and the other HPS would look wierd and wouldnt have good coverage of both lights in the tank. And 2MH and 1 HPS was my primary choice, but running 3 lights is getting very expensive. They make ballasts (Lumatek) that can drive both MH or HPS so you could switch if you dont like the look - the problem is the cheapest I have seen them (online) is $170 for just the ballast. They do claim pretty high effeciencies though.

Another thing I have learned researching HPS is that the 270W Super Argo bulb is supposed to be realy good and features a higher lumen effeciency and more blue spectrum than other sodium lamps. And also its been said that it will even be more effecient if placed in a 250W ballast and the blue is said to be brought out more in a 250W ballast.

The bulbs are slightly cheaper than MH, the Super Argo bulb sells for $50, but the Lumatek Balllast($170/250W) will cost you more compared to MH - Icecap for example($115/250W). All the other parts are universal with MH.