how long you leave the light on???

[Ducatti]

how many hours is it again that you leave on per day?? was it 12 hours for a 10g nano???

[ruuskystar]

it's kinda up to you. if your seeing algae blooms you can minimize your light per day. for a regular daylight photo period between 8-12 hours is usually the norm I believe.

[KevinFJB]

I leave mine on 12hrs - have had a few mild algae blooms (brown, a little red cyano, and hair, but all cleared.

[VWfisher]

10 hours seems to work for me.

[cancruiser]

10 hours seems to be working for me as well.

[Aquadude]

11 hours, plus a 1/2 hour sunrise in the morning and 1/2 hour sunset in the evening. Contolled by my custom made lamp timer that gradually brightens and dims a halogen lamp in the light hood.

[Kutter]

I have my VHO's on for 12 hours and my Metal Halides on for 10 hours.