Why run lights 16 hours a day (Phyto cultures)?

[melev]

What is the problem with running the lights 24 hours a day? I'm starting my own culture for the first time, and it has been 72 hours so far and it already is bright green. LIghts have been on 16 hours a day, off 8 hours.

But why can't we just run them 24 hours a day? Wouldn't that speed up the culture time, to where you have newly made phyto in 3 days instead of 7?

[laxing22]

Is this a macro alge only tank? If so, nothing is wrond with 16 hours of light. In fact, if you are strickly growing it for production. 20 or 22 hours would probally be ok. But I am sure, there needs to be at least a couple hours of dark for the plant to rest. Most plants resperate diferently at night and consume food differently. I don't see why you could not run them for 24 hours streight for a few days (especially with fresh cuttings) though.

[phdezra]

Tangentially, don't the Ecosystems say to run lights 24 hours a day over the sump/refugium when containing macroalgae used to remove nutrients?

[stereomandan]

I have read that the culture has it's highest growth time when the lights are off. They need at least 16 hours of light though to keep the culture going. They found this combo to be the best. I have since gone to the 16 hour route and it still works great. My culture does looks darker green than it did with my first cultures when I had the lights on 24/7. Plus it saves on electricity.

I think it was an article from advanced aquariasts.

Dan

[stereomandan]

I think this is a great article. I think this is where the 16 hr lighting period is addressed

http://www.advancedaquarist.com/issues/aug2002/breeder.htm

A quote from the article:
"Next let’s discuss some tips that will allow us to maximize our phytoplankton yields and accelerate their growth. The first parameter to focus on is lighting. If we provide lighting for 16 hours daily, we should get the best growth. Remember cellular growth and protein production occurs during the plants dark cycle and if we were to illuminate for 24hrs we would not increase our yield of phytoplanktons proportionally. It is particularly important to know that many species of phytoplanktons poorly tolerate 24 hour photoperiods."

Dan

[melev]

Thank you Dan. I love a difinitive answer in this hobby. Especially when they are so few and far between.

Got one for WPG? :lol: :lol: :lol: