they also eat their food off the dirt and chow down on unwashed insects and plants. Most algae is of the blue-green variety anyway which is not only non-toxic but actually has some nutritional value.I've never had any build up in my nipples, use the vertical, no sunlight, no algae. Even if I did, is it a really big deal? Chickens eat their own poop.
That's not to say you should ignore common sanitation and let your watering system get all funk.
