Hey. I was lucky enough this week to visit a commercial outdoor hydroponic farm. The guy grows top quality herbs for 5 star chefs and flowers for garden show's etc. He grew primarily in an NFT setup but was switching to coco. Now one thing i noticed is that he had algae growing in all the channels and around the drainage pipes. I didn't wanna say anything as i thought it might be a little rude but this goes against my whole beleif that everything must be kept surgically clean. Is this the case or because he's growing outdoors is it ok to lapse on the cleanliness'
Algae, as itself, isn't bad for your garden. It will form anywhere you have air, water, and light. However, Algae will attract certain kinds of gnat. The gnats feed off of the algae, and if you get enough of them, they will infest your bud. If you keep anything that is wet in the dark, you won't get algae. Algae needs light to grow. Some people who grow hydro will cover everything with plastic except for a small area directly around the stem. They sell a special kind of Clay/waxy spread that you can cover that exposed area with that will keep the algae from growing. I will try and find out what it is called.
Algae in open trays is an ongoing issue with large Hydro ops... Nutrients + Light = Algae + Oxygen Algae + Oxygen + Nutrients = Less Nutrients + More Algae One of the reason I gave up on flat-bed ebb & flow was fighting the algae battle. A "healthy" algae colony will suck down CO2 like a sponge while it is getting light. Removal of CO2 from water causes pH to rise. Turn the lights out and CO2 rises and pH falls. In NFT and DWC systems there is not a whole lot of opportunity for sunlight to get into the reservoir but once the algae is there the added oxygen will keep it alive and eating nutrients. The only way to keep on top of algae is to keep it clean (and keep the sunlight out). So cleanliness is a good mantra...
Yeah well i'm a bit of clean freak as far as my room goes, if you knew me in person you'd think that's weird but i've always seen hydro as a fairly fragile thing and done my best to keep bugs and bacteria out. I'm guessing this dude musn't have that much of a problem or he would have fixed it by now.