Light burn, deficiency, or too many nutes?

[MerryMonk]

Hi all, I’m growing three auotflowers in FFOF/ perlite indoor under a mars hydro 600. Here’s a link to my journal.Journal
they are all 8 weeks old tomorrow , and the WW has been flowering for 3 weeks. I found some brown spots on the top cola of my white widow-some are on the tips, while some is in the middle of the leaves. Is this something to worry about? I have been giving 1/2 strength fox farms big bloom/ tiger bloom nutes every other feeding, but was ready to switch her to all water starting with the next watering.

The other two girls are lemon autos- I also noticed some spotting on big, old fan leaves, but nothing on the new growth. Should I be concerned?

 

[oldsmokey]

@Emilya is very good at diagnosing these things maybe she has some input. Also if you could get a picture of the whole plant?

 

[ridefas78]

i'm new to learning what the leaves are telling but i think that "rust" like leaves are either nitrogen or not enough cal-mag. i hope someone will chime in to correct me if i'm wrong*more likely am* lol

 

[CanadianJim]

Looks like a calcium issue to me.

 

[Emilya Green]

The deficiency is calcium, and the problem is that you are giving half strength nutes and then on top of that are actually thinking about starving your plant at the end, which will of course make the problem a LOT worse. Trust the nutes and the manufacturer's advice on how to use them, or throw them in the trash, that is my advice. Nothing in the feeding chart says to starve your plants at the end either, but there is a suggestion to do a 3x the container sized flush a few times. If you misuse the nutes, trusting instead online advice on how to use them contrary to the instructions, you can expect problems.

 

[MerryMonk]

Thanks for the advice- you are correct, there is conflicting information on the internet! I had planned on going with a full regimen of nutrients, but I read a lot online about Fox Farms Ocean Forest being a “hot” soil that one didn’t have to add a lot of nutrients. Since they’ve been chugging along nicely, I figured everything was going well! I will kick up their feeding to a full schedule, and see if they respond. Your advice to

suggestion to do a 3x the container sized flush a few times-

means for my 5 gallon containers, I should run 15 gallons of water through each plant three times? When should I do these flushes, and who has a good write up of flushing?
I enjoyed your essay on watering Emilya!

 

[Emilya Green]

no, just a one time flush of 15 gallons will be fine... do it on a regular water day and just call it a good runoff. If you check the FF feeding schedule you will find that they call for flushes several times during the grow. I would suggest doing it as you come out of veg and change to the flowering nutes and once at the 6 week point as you are going into the last two week push to build the buds, and any other time that you notice the plants stalling for any reason.

Flushing is much misunderstood these days, after one of the grow websites started confusing the term with the ridiculous practice of giving only water at the end of the grow to starve the plants into submission, so what is written about it is oftentimes not trusted and much argued about. Because of the internet gurus, everyone now seems to think that you need to flush, or starve the plant for the last two weeks of its life. There a lot of people growing a lot of underdeveloped pot out there because of these online know it alls and their bad advice. Trust nothing you read online, and especially what some showboat puts out on youtube. Verify anything you can in your own garden, and see for yourself. This is the ONLY way to separate fact from fiction, in this brave new online world.
What I have realized is that the more I write about this, and the more times that I answer questions about flushing in the way that I just have, google searches are finding me more and more easily and bringing people to this forum. The more times I explain this, the better the chance that I can help to change the world. Thank you for helping me in my quest and in return, you are becoming a great gardener of weeds.

 

[MerryMonk]

Well,I followed advice, and did a full flush followed by two feedings at full strength (Water in between). The girls liked the flush, but the discoloring continued on my white widow, and what was a little rust on my first Lemon on has now covered most of the cola- help!?

is this just a reaction to the nutes? I know working in soil makes things slower, both problems and solutions to show up, so is this just a show of catching up from lack of nutes earlier? I am concerned about giving this much nutrients to the auto flowers- everything I read tells me they don’t need as much as photo period plants do. Is this nutrient burn? Is this going to affect my final product in terms of taste?
thanks to those who Have already helped!

 

[Emilya Green]

Well,I followed advice, and did a full flush followed by two feedings at full strength (Water in between). The girls liked the flush, but the discoloring continued on my white widow, and what was a little rust on my first Lemon on has now covered most of the cola- help!?

is this just a reaction to the nutes? I know working in soil makes things slower, both problems and solutions to show up, so is this just a show of catching up from lack of nutes earlier? I am concerned about giving this much nutrients to the auto flowers- everything I read tells me they don’t need as much as photo period plants do. Is this nutrient burn? Is this going to affect my final product in terms of taste?
thanks to those who Have already helped!

several misconceptions here... soil does not make things slower necessarily...
It looks like the flush and nutes helped the others, but White Widow is known to be a nutrient hog, and the symptoms you are seeing up top confirm that... she needs more than the others do. Up her feed a bit and you will get rid of that calcium deficiency that is showing there.
There indeed is a lot of horrible advice written out there about our plants, especially autos. Autos are fast growing plants and because of that, they can have the same nutrient needs as photos, if not even more so. Don't believe everything you read, unfortunately, these days you can not count on it as being true. Anyone advising you to automatically use 1/2 strength nutes for an auto, is blowing bro-science BS at you. I challenge you to find ANY nutrient company feeding chart that specifically gives a different dosage of nutes for Autos vs Photo plants. It does not exist. Maybe you need to change that which you are reading for your primary information.

Is this going to change the taste of your final product? No, that is locked in the genetics. What a deficiency will do is affect the plant's ability to fully express itself... and if even infinitesimally, not having proper nutrition will affect the quality and quantity of your harvest.