Quick quantum ballast question!

I have 3 600 watt quantums and i was wondering, can i switch the power say from 100 to 75% while the ballast is running or does it have to be off?

I now switch when power is off but was thinking and im sure its in the manual but.... This is what i come on here for.

Thanks

A2SEED

You can switch it while its on, according to the mfr just dont 'toggle' back and forth repeatedly.

i use lumatek which are very similar. i always turn the power off first. wait at least 5 minutes before relighting a bulb. they say 20-30 minutes but i think 5 is plenty if you have cool tubes. otherwise you risk prematurely wearing your equipment.

UPDATE:

The dimming switch is located on the front of your ballast just above the lamp cord. Always allow 30 seconds between the different output settings to allow your ballast to draw the proper amount of power and charge your bulb to the desired setting. Do not rapidly toggle the control back and forth as this may cause damage to your ballast and/or bulb.

Welcome to Quantum Horticulture…..You are about to experience perfection.

source: http://www.quantumhort.com/instructions.html

Thanks alot fellas.

anytime bruh!

This is interesting because I've only dimmed them while they were on. My hydro store guy told me that it wasn't good for the bulbs to be started up at partial power.