RIU guidance needed

Hey there everyone. So I have a problem in my garden, let me give you the run down and we can go from there.

Plants are almost 8weeks old Stand any where from 16 to 18.5 inch tall. Their feeding schedule goes something like this. Water with Super Plant tonic, Water, Feed 1/4str Grow Big, 1/2str CalMag, 1/8 str Flora Nova Grow. Just added Fish Mix at 1/4str last feed which was on the 8th. Some times I dont use the Cal Mag in the feeding. Temps run hot at about 88-94. Humidity is low at about 35%. Ph of soil is about6.8-7.0

Here is the problem I am having, older fan leaves are turning yellow and then turning brown at the tips. I have some pics any input would really help. If you need any other info let me know.

My thought is that I may be light on my feedings. Im guessing they are lacking a mirco nute like Zinc but what do you guys think. This has been going on for maybe a week now. Its very slow and does not kill very may leaves but has not stopped and now I am starting to worry.

your canopy is quite dense.

to me it looks like 2 possibilities N def or not enough light hitting the lower regions of your plants.


J

I would second Jonhamon's notion that not enough light is getting to the lower branches-- they are packed pretty tight. You are also running too hot (note the folding/creasing of the younger leaves)-- though this probably has little to do with your leaf drop.

You didn't mention the medium for your grow. If you have a soil based mix, you probably don't need to up the nutes. Be careful increasing the nutes, high temps and heavy nutes can be a bad mix. The plants actually look pretty healthy to me.

i think its under fertilized. grow big and flora nova are probably small npks that need to be applied twice a week. to fix it give it a shot of mg all purpose or somthing like jacks classic. those are big plants so probably are deficient.

Im growing in a mix of 45% FF ocean forest 40% Bio Bizz All mix and 15% perlite. plants are packed a little and all the under foilage is either going to be trimmed or trimmed and turned into clones. I am running a little behind on all of that, Id say about a week or so. I need to transplant and get these ladies into flowering soon. Id hope by mid next week.....

I still need to setup some kind of exhaust system shouldnt be to hard since my window is right there.

any one else have any idea or are these guys on point. I am still leaning towards a Nitro problem or a Zinc problem....

Feed the plants yesterday. Hopefully in the next couple of days I will see the signs diminish.

still happening check it out on my little journal I have going