It can cause algae outbreaks within the aquarium. I have 3 rooms in my house, so I'm limited on where my tanks can go. My living room, which is the only option, is almost solid windows on 3/4 sides. My 36 gal
has no sunlight hit it and is perfect, I can leave it be with only minor use of my mag float. My 55 on the other hand is surrounded by windows. When my sump went down which took out both my fuge and my dual reactor. This normally would be fine since I just moved my skimmer onto hob
, put a hob
filter on, and did slightly larger water changed w/ my ro
setup. Without my fuge, my algae exploded. It literally turned my rock into a field of hair algae. It took almost 2 months to get under control again. Even with everything going with my fuge again, just the sunlight moving across the front of my tank as it rises is enough to cause a film algae growth that was not there prior to sunrise. I am only talking 2 hours of it moving across the length of my tank, if that.
Now, the flip side of this is that there are actual uses for natural sunlight. I'll admit that even though it causes algae issues in my tank, my corals look amazing. They have never looked this good, and I say this as there used to be a cabnet blocking the sun to the tank. There are people who utilize natural sunlight for their reef aquariums. When I first got started in November, one of the builds I loved following was a large build that a guy built as a divider between his kitchen and dining room, or something like that. He utilized natural sunlight that came in through a port in the roof, though I do not recall what setup he had that was able to fully utilize the sun's rays.