what kind of algae will sunlight grow?

my 100g display is spotless when it comes to algae (except coralline which is all over the place). It wasn't always like that I used to have a lot of hair algae.

Can I open the windows by my tank to give my corals a little extra light every so often?

I am not concerned about macro algae, I have already over come a lot of macro algae with my livestock. (Rabbitfish, Yellow Tang, Two golf ball sized mexican turbo snails all love hair algae)


I am a little concerned about a phyto bloom. I wouldn't mind producing some phyto in my tank since I am dosing live phytoplankten for the corals anyway... as long as it didn't affect water quality/visibility.


I don't want to leave the windows open all the time, just give the corals a little extra light which may help them out since I only have PCs.

 

To answer the direct question of your title: "What kind of algae will sunlight grow," the answer is anything that's green, or contains components of green pigmentation. Chlorophyll is what reacts to light, and is the catalyst for photosynthesis.

If your paramaters are in check, and you don't have nuisance algae issues, then chances are good that letting some light in through the windows won't change your scenario. You should be fine.

 

I have a 50 gallon that receives natural light every morning for about 3 hours. I too am only running PC's. The only difference I have noticed with the natural and the PC's is the side where the sunlight comes in will get a little more green film algae on the glass, but even that is not too much. The corals love it!

 

Thanks reefsparky. I should have phrased my title better, I realize it is going to feed all organisms requiring photosynthesis to grow. I was more hoping someone would put my mind at ease that it won't cause such a thick phyto bloom I won't be able to see my livestock, which you did in your second paragraph.