dimmer or 2 ballasts

[toddpolish]

to recreate sunrise/sunset, do you recommend a dimmer or a 2nd ballast.
Right now Ihave 2-50/50 vho and 2 actinic
what are the pros/cons to each?
thx for feedback.

 

[slick]

I'm not sure but I don't think you can use a dimmer on these ballast.

 

[toddpolish]

on the icecap? yes, there's a spot for a dimmer