Fungal Issues

So I have a small problem. A day or so ago, I noticed a couple of older leaves had small brown spots all over them with the margins toward the tips darkening and becoming crisp. The plants are 'Blue Satellite'. Grown in GreenWorld potting mix, and fertilized with Botanicare Bloom for Soil and Liquid Karma. Air circulation and ventilation is adequate.



This is my second run and I'm using a new setup, so I'm still dialling it in. Going into the 4th week of flower, I have some issues with over-watering/poor drainage, as well as over-fertilizing (No burn, though.). The colder weather has thrown my climate out of whack, too. Now my cabinet is 28 during the 'day' and goes down as low as 18 at 'night' with the humidity going from 50 to 70. The swing in temp/humidity, I figure, is the culprit in causing the fungal issues.

To solve these problems, I have: Stabbed a bunch of holes in the grow bags to encourage air exchange and improve drainage; Last watering was straight water (spring water, low EC.); Opened more hot air vents to for heat; Added a dehumidifier outside grow space.

Hopefully these measures will bring everything into check. I think the temperature swing aren't going away, but if I can provide a supply of dry air, it shouldn't matter too much.

Question is: Should I remove infected leaves (Leaning this way.) or what is my threshold for doing so? Is this the right diagnosis, or am I missing something?

Past experiences with this, or tips to solve it would be a great help.

Cheers,
sk'mo

Hey man. Looks like leaf spot fungus. It's quite hard to stop permanently without to much effort but looks like you've made a start. But yes, you should take off the infected leaves

Try and get something like Biobizz Leafcoat, which strengthens plants against fungus attacks. Its a spray you spray over the leafs that creates a permeable layer over the leafs and protects it. Or you can go the garlic route, which i must say helped a little in the past but was not a cure.

You will also need to clean your grow space. Good luck.

Thanks for the advice. Not sure that BioBizz is available in my area, though. Looking at/for a garlic and baking soda mixture from to use a a leaf wipe. I'm not sure I want to spray the buds with anything right now. Any recipes? I'm growing for medicinal use and I need to stay as organic as possible.

On a happier note, the RH outside the grow space is down to 45%. I'll be checking the grow space just before lights on to see what its like inside. *fingers crossed*

Thanks for the help!