Alright, so I have one plant under 4x26w cfls. Lately, I have been noticing slight burning on the tips of the leaves. I have already backed the lights up a bit and removed some of the more damaged leaves. I also started flowering a couple weeks ago. Is there anything else I should be doing to prevent more burning? Any help is appreciated.
^^ correct. Burnt leaf tips is usually the first sign of overfeeding. Another thing to consider is which medium you're using? If it's a high quality organic soil like fox farms OF, then it already has a high ppm and you don't want to go over 1.8 EC or 1250ppm roughly. A lot of times the feeding schedules don't account for this and if you're mixing carefully as you say, then you're probably following it to a tee, which means too much. Which product line are you on? I've heard Canna recommends overly high amounts. A lot of people recommend going half strength and then slowly increasing to see how much they can handle, looks like you've past the point they can handle. It may also be the frequency of the feedings like the above poster mentioned. Leave a fresh water feeding in between regular feedings, or make lighter feedings. Best of luck to you, peace