Mold or other Bacteria Growth a concern??

Hey guys thinkin about DWC for a minute.

There is the water resevoir which is mostly sealed off (can beathe only through say leaks around the lid and through the hydroton rock net cups somewhat. But no light should mean no algae, right?

But what about mold??

Is this why temperature control is key? How humid or what air temp should my res have, and to what water temp ratio, you know what I mean?? Or is this why we replenish the res water every 2 weeks or 1 week or so?

For instance one time I had a bubble container which I used to germinate a seed with some water and a wet paper towel piece inside. It usually works but one time I had this black stuff beginning to grow all over the paper and eventually the seed. The seed could not be rid of this and I had to chuck it. This is mold I'm pretty sure. Slightly warm temps, moist, 100% humidity or so...

What do y'all think about this and what do YOU do to prevent it??

*shrug*

u wana make sure theres no light leaks where u mentioned the air leaks.,.,if light hits that water its basically "giving life" to bad bacteria.,.,.

ok so no light = no growth? I guess it is fundamentals of life here on earth, eh?

I need more 12/12 cycles I think.

Yeah make sure no light gets into the res. Also, the res temp should be kept around 65 for optimal dissolved oxygen and to prevent the growth of algae and bacteria like root rot. Humidity is also another big factor. With 100% humidity you're almost guaranteed mold. Humidity in your grow area should be kept between 40 and 50%. Good luck!