This seemed to pop up in the past day or so. Littl...

Hey there, so with the additional lights it can often help your yields tremendously. I believe a general recommendation would be between 18-24 inches, but whatever your space will allow will have to do. LEDs are notorious for light burn and it can look like your sporting, my other thought was calmag. I see it's in your lineup so if you're not seeing anymore leaves affect that could be it, if not definitely adjust your lights. I've seen my plants suffer from getting liquids on the leaves, but typically only during light hours, so if you're spraying or spilling, try doing it at night. 😊 best of luck, they really are beauties.

That looks like a calcium deficiency. Looking at the chart, nothing else looks similar to calcium deficiency. Take a look: http://loudclouds.co/wp-content/uploads/2016/07/marijuana-deficiency-chart.jpg So it looks like calmag will fix it.

Calcium deficiency starts at the new growth first because Ca is semimobile which makes it hard to move around the plant so its signs show at the top/young leaves. Since your rust.brown spots started on older growth it is magnesium. Mg is mobile so it will move from the bottom of the plant to the top. Try adding epsom salts or cal/mag (preferably more mag).

The little brown spots are not a phosphorus deficiency but a calcium dificiency this is very common in hydroponics. I would recommend using a calcium supplement like cal-mag from botanicare. Phosphorus deficiencies cause larger browning patches across the leaf. You can find examples of both on growweedeasy.com. Also calcium is best absorbed into the plant between a ph of 6.2-6.5. I understand this is not ideal for hydroponics but it is important to make a temporary adjustment to perhaps 6ph. Hope this is helpful. Good luck!

Hi @BeardedTree! Brown/bronze spots, dark leaves, purple stems --> it's a Phosphorous deficiency. This may come from wrong pH, or pH fluctuations, or not enough Phosphorous in her nutrients intakes. Your pH seems fine, if you're 100% sure your pH-tester is correctly calibrated, then this must be your last feedings. Try to increase her Phosphorous intakes for the next waterings, and see how it goes. Hope this helps, I'll be around, keep us up-to-date and happy growing!