rust spots on leaves help

Hi there i have an auto plant about 5 weeks into the 8 week time so well on with budding now however it is gradually getting more and more rust spots on the leaves and some of the fan leaves have started going yellow and crispy at the ends,plant is being grown in soil and been using biobizz nutrients and watering using room temperature water ph of water run of is around 6 so im clueless as to why this is getting progressively worse so any help would be greatly appreciated, thanks.

I would add calmag for the next two weeks.
If you want a better answer post your
soil info
along with any other pertinent info.
Best of luck.
A whole plant pic is good too if possible
to show the overall vigor and extent of problems

Looks like a potassium deficiency to me.



Got any PK1314 or or anything with a higher K.



J

What you have there looks like a classic potassium deficiency according to my chart.

You arent snipping leaves off are you? Leave them!!

Well I mean you obviously snipped that one in the photo off so that is my reason to believe you snipped the others off. Just dont want you cutting them off unnecessarily!

Not potassium def. Phos and calcium def. Potassium defs show along the edges before the tips. Add more phos and cal. Not mag. Keep them separate.

Heres a pic i just took now and it was only the 1 leaf i cut of the plant, its only a tiny plant as it is. What are my best doing to sort this out then? nutrients ive got are biogrow which is 4-3-6 and biobloom is 2-7-4 and the compost is just standard compost from garden centre, it does say its neutral ph and has 3 months nutrients in it.

what should i be doing to sort this plant out then? still not exactly sure what i need to treat it for with people saying different things.

You're saying you're growing with pure compost? Am I reading that right?

I'm not big into soil my self, but I'm pretty sure compost is supposed to be a part of soil, not the whole thing.

I'm not 100% positive, but it looks like you have a phosphorous deficiency and should add the biobloom you have. That will also help even if it turns out being a potassium deficiency..

its just generic potting compost from the garden centre growing vegetables in and ok thanks