Chaeto

I think you will have to hang a light by it.
I don't think it has to be a fancy light.
we will see what every one has to say

 

yes its better to have a clamp on light or a light that will sit on your sump i run my chaeto for 12 hrs a day have my light on timer i use a compact bulb 24 watts

 

The best thing to do is to run the sump light on reverse light cycle of your aquarium. It will be a huge help to keep your ph that much more stable, will help slightly keep your tank temp fluctuations down, and also, when it's "night time" in your sump/refugium, all the little pods will be crawling around more and end up getting sucked in the return pump and get kicked out during your display tank's "day time". As for what kind of light, any clamp on or cheap light will do, usually the cheaper the better! haha

 

well said