MH Bulbs???

[howdy20012002]

How do I tell what kind of MH bulbs I need.
Sounds like a stupid question, but I have no idea what type I have..just that they are 400 watt.
How can I tell what type they are?
thanks
Neal

[reeferaddict]

There should be some markings on the bulb... if not they're probably hydroponics bulbs, which CAN be used for a reef tank but not optimally. You want at least 6500K bulbs if not 10,000 up to 20,000K bulbs...

[TheReefGeek]

To find out what kinds of bulbs you can run, check your ballasts.

There will be some numbers on it.

M59 is a 400W probe start.
M135 is a 400W pulse-start.

Pulse start ballasts have transformer, capacitor, and ignitor.
Probe starts only have a transformer and capacitor.

Then you have to match your new bulbs to the ballasts.