Tank lights AND daylight light

[Lynnzer]

I have 2 tanks in a spare bedroom at present. One is directly under the window ledge and the other which is on an adjacent wall is set higher at a level above the window ledge That tank wouldn't get direct sunlight where the other will, but of late afternoon with little intensity.
I have 2 x Kessil A160WE's over the higher tank and am running an unknown tank width light over the lower one. That was originally bought for my freshwater tanks, however it does have a wonderful blue option on it when I close down the white light. Never mind that so much though as I have a couple of other lights on order with my intention to have a good selection of corals in the tank.
I know there's a lot to this sort of thing and I intend to hire a PAR meter shortly when the new light arrive to set things up as best as I can.

In the meantime though, I wonder if the daylight in the room, and the late afternoon direct sunlight albeit English sunlight, will have any detrimental effect. I have blackout curtains for the windows as well as ordinary blinds which I can use to keep the room dark but do I need to to?
Would the daylight have any effect I would need to control?

 

[blaxsun]

You will see a bit more algae growth with natural sunlight.

 

[Timfish]

I have a system that gets between 1/2 hour and 2 hours of sunlight depending on time of year. Because of the different spectrum and varying intensity I've had trouble with some corals but not others. ABsicly the coral that need a specific spectrum and intensity to develop specific fluorescing and chromo proteins would do well for a few months then as the light field changed with the seasons they would decline. So you'll have to do some experimenting to see what does well but it goes without saying to start with hardy varieties.

 

[Jmcg89]

I have my tank by a sliding door that gets morning sun and noticed a big difference in less algae after getting blackout curtains.

 

[o2manyfish]

I have a 1500g system. A 750g display tank in the house and 2 outdoor 180g frag tanks. I have been keeping outdoor frag tanks in direct sunlight for 20 years now.

The frag tanks usually have less algae to clean off the glass.

The corals in the outdoor tanks grow 3-5x faster than those in the display tank inside the house.

The colors are different, until you come outside at night with a blue light and see how amazing the colors are under blue light having been grown in the sunlight.

And the sunlight has great healing properties. I pick up browned out colonies from local stores and in as little as 5 days, during the summer, can have a colored colony. In 2 weeks it's a beauty. The recovery time in sunlight is amazing.

Dave B