Does sun make algae in fish tanks?

You bet ya, having a tank in direct sunlight is never a good idea unluess you have it in a pitch black room otherwise and don't have a light. Fish need a regular day night cycle just like we do but it doesn't matter what kinda light it is. But ya dirsct sunlight both heats up the water and causes algae to grow faster. Take the tank out of the sun and do more water changes and gravel vacuums to remove the nutreints the algae lives off of. That should help your problem. Good Luck

The sun not only makes a heap amount of green algae in your tank, it also raises the temperature and then at night it drops too much, making it stressful for your fish.

Yes, it does, so it is preferred that you not place any tank near a window or bright light since it makes algae break out and start growing like crazy.

Algae needs light to grow. More light, more algae.

Sunlight is very bright and will cause LOTS of algae to grow.

Ian

yes