Thank you for the info, there seems to be a few things that I need to change.I had a very similar problem with my last grow of OG Kush (My Northern Lights faired better) and I can see why OG Kush is considered an intermediate grow and not a beginners. It's very sensitive to nutrients inputs and watering. Looks like your going through a lockout. I'm on my 2nd grow of OG Kush, side by side with a White Widow, this time the OG Kush is doing better than my first attempt at it, like you I'm not celebrating till that 4th week of truth, so we'll see. But burnt tips and yellowing is a lockout. For watering you want to aim at 5 to 10% volume of your pot at a time. Three days is safe but stay on top of your soils moisture on a daily basis. Tiger Bloom sounds like a synthetic nutrient and those do best around 5.6-5.8 pH. Not sure how folks here feel about measure EC before and after but you might want to look into that. But from what I'm seeing from the pics, your overdoing it with the nutes with probably not enough runoff. You want 10-20% runoff when watering. (That 5-10% watering per pot volume is a good guide for organic soil growers ) but for synthetic growers aim for 10 to 20% runoff when watering to avoid salt build up in the media. my 2.cents. I went everywhere with that one...