Hi people, my first trip to the infirmary

My Himalaya Blue Diesel Auto that is about 1.5 months old and approx 2 after showing sex is showing some ugly looking brown/rust coloured spots in between the leaf veins mainly on the lower fans leaves.

The leaves seem to feel very dry and crispy too, and seemed to have cupped slightly and drooped as well. New growth seems fine, and the plant seems healthy enough otherwise. It doesn't seem to be a huge problem yet, but I imagine if it got worse it could well be.

Here's some pics:







The plant is outside grown in a 8 litre polypot in B&Q multipurpose compost. I started feeding it some Tomorite about 2 weeks ago. The plan was to only feed it once a week, but I think I may have overdone it as I gave it 3 feeds in about 6 days. Silly I know, but it was just because it been very hot and dry here the last week so I was watering more frequently I thought I might as well add some food too. Out of those 3 feeds 2 were at 1/2 strength.

The Tomorite NPK ratio is: 4/4.5/8 with added Magnesium and seaweed extract.

When I've googled brown rust spot on leaves alot of people seem to be saying its a Magnesium deficiency however as the Tomorite contains magnesium surely it can't be that.

I think I've just overdone the feed and have flushed the plant thoroughly today, however I thought I'd best seek some expert advise!