Autoflower Shortrider 4th week flowering. Yellow/purple leaves. Brown spots!

My shortrider is in the 4th week of flowering now and is looking a bit pathetic. I have tried to pinpoint the problem but there is so much wrong it is hard where to begin! Here are pictures and information on my situation


FoxFarm Ocean Forest soil
2 Gallon Pot
General Organics Nutes (per gallon H20). It takes about a half gallon per watering
-2 tsp BioThrive Bloom
-1 tsp. BioBud
-1/2 tsp Diamond Black Humic Acid (to lower solution pH)
*watered every 2-3 days

pH of solution = 6.4 - 6.6
temp = 81 F
humidity = 35%

24 hour light cycle
100 Watt LED lighthouse flowering UFO

Additional info
- the soil seems to be very tight. I can't dig my finger down more than 1 inch. I used a knife around the edges to try to aerate the soil, but I don't know if it did much.
- The the tips of the topmost leaves of the main cola are the ones that are turning purple; the rest are yellow with brown spots.
- grown in a tent with 171 cfm fan, a hydroponic system with 3 seedlings under 96 watts of florescent lighting, and a single non-oscillating fan

Any input would be appreciated. If any more information is needed let me know.

Thanks!

I am guessing potassium deficiency, but the tips look burned. Did you over fertilize in the past ? or is that a new symptom?

The pot is pretty small...I can see that being rootbound pretty good...but its way too late to repot it...just give it a good boost of P/K and some cal/mag and hope for the best to finish it out...also take a PH reading of your soil not the solution...you want that at about 6.5-6.8

temp could be a lil high too, but these guys know better what theyre talking about than i do

Yep, burned her in the 3rd week. I added nutes too soon; the combo of ocean forest + nutes was too much. The problem that is new is the purpling leaves of the main cola and the brown spots all over the new growth. The pH of the run off is around 6.5 too. I don't have a probe so I can't check the pH of the soil.

Also, I tied her down in different spots. She is actually about 20 inches tall, even though she looks like she is 12

yer probably ok on the PH...its probably just rootbound and salt locked at this point...so unless you want to try a flush...thats about all you could really do at this point i think...