New grower having problems

[SweetTrees]

First time grower doing autoflower gorilla glue barneyfarms.
5 weeks in and experiencing problems, doing 3 plants each in 4L tubs.
2 of the plants originally grew very good nice colour and size they grew fast.
The other 3rd plant grew slow, had dark leaves with pointy leaves which generally looked unhealthy.
i kept it going as i assumed it was a slow grower, didnt see obvious signs of budrot.
The other 2 plants have had one or two yellow coloured leaves die and fall off at the bottom but the rest stayed generally healthy, now the top leaves are developing yellow spots and the plant has “witches finger” leaves pointing down and curling at the end.

Im using hornet coco feed a + b 8ml ea per litre water
Mills c4 5ml per litre water
Mills ultimate pk 4ml per litre water
Mills vitalize 0.4ml per litre water
I mix them all in the same litre of water and divide the water between the 3 plants.

Im using a 600W light about 2 feet above plants, 18 hours light 6 sleep.
27* degrees
30% humidity

Can someone tell me what im doing wrong please do i need to get rid of the 3rd plant is it affecting the other 2

 

[DCLXVI]

Well, are you growing in coco coir? I see coco nutrients listed. If so, and the coco looks dry from the pics, are you watering to runoff? Coco needs to stay "wet" and an approximate 20% runoff volume usually works well to prevent nute/salt buildup. What is the solution pH you are giving the plants? 5.8-6.2 is a nice spot for coco.

If the leaves are dark green and clawing tip down that is usually too much Nitrogen. I am unfamiliar with the Mills line, however, when you mix all of those products together, what is the nutrient solution EC/ppm and pH values? You may be giving too strong, wrong pH, not enough volume or frequency. That's all I can suggest as of now.

I looked at the Mills website, ultimate PK would only be added towards the end of the bloom phase and I think you are at the early/beginning stages of bloom. Perhaps drop that first to help balance things out.

C4 looks to be a veg/bloom transition period product, if you are at week 5/mid flower you can probably drop that as well.

I cannot find a website for Hornet nutrients, only a brief description on a single hydroshop website. They mention that you only need Hornet A/B for both veg/bloom phases. I suspect 8ml per litre of both A and B is incredibly strong.

What type of water are you using? Tap water? Jugs of distilled from the store? Reverse osmosis? Most nutrient lines are designed around 0 EC water. If you are using tap water, plus 16ml nutes, plus C4, plus ultimate, plus vitalize.... I suspect you are overdosing your plants with nutrients and things are extremely out of balance.

Do this: (some people like EC some like ppm, its PG Tips v Lipton/Twinnings)

Do you have an EC/PPM tester?

Do you have a pH pen/meter/tester?

Are you using tap water or distilled/reverse osmosis water?

If tap water, what is the pH and EC?

If you mix 1ml of Hornet A and B into 1L of water, let it sit a few minutes, what is the EC and pH?

Start there and we might be able to sort out your grow into something decent in the end. I am far from an expert myself but am acutely aware the growing pains of being new. Pun intended.

 

[SweetTrees]

I’m using “100% Coir” i keep the soil moist and do not allow it to dry. Usually every couple days i will give it a good water, sometimes spraying the soil to keep it damp. Im using 6.0 PH, i have a metre and ph up+down. I use tap water but its fairly good clean water where im from it comes to 6.3 PH.
How can i reduce the amount of nitrogen?
i also used a “jurrassic co2 nutrient spray” on the plants.
i follow a Mills guide chart which suggests using all of the products throughout the grow although im not entirely sure thats accurate as ive also been told otherwise. I was told Mills is a premium product and it was 3/4x the cost more then most products ive seen about.
I will admit i dont have EC/ppm metre but will order now for next day delivery.

 

[CannabisMingus]

I don't know that nute line but it looks like lockout from excessive nutrients. I don't do coco so I'll defer to those who know what to do to fix this problem is this media. (I guess that makes me 0 for 2) Good luck!

 

[JP1]

I've never heard of that the nute line but here's the feed chart for the hornet Coco feed from growdiaries. Supposed to be used from sprout though flower. You're at like 4x of what you should be using of that product alone. Should be like 2ml of each. Also adding way too much of everything, and the foliar will make it worse.
I would flush the hell out of those pots. 8 gallons of 5.8ph water with some calmag. Each. Then just use the 2ml each of the grow a+b, with probably 1ml calmag and stick with just that for a while. Gotta water the coco with nutrients every day. And gotta be to runoff at least a couple times a week. pH also super important. Good thing about Coco is it's easy to flush a problem and start fresh. Good luck!

 

[420autoflower]

Have you checked under your leaves for spider mites or other insects?

 

[Silver]

The issue in my opinion is that you're treating coco like soil..you should be watering every day till at least 20% runoff, you shouldn't be skipping days, especially at this stage for the plants.

Looks like there is some nute build up, on top of the fact your most likely feeding too much looking at the numbers which is making matters worse, along with the super low humidity.

DCLXVI has given you some really good advice when growing in coco in this thread already, have a really good read through and it will help a LOT.

 

[DCLXVI]

Aye, glad to see someone found a Hornet guide. Looks like 4ml is their recommended max dose. You are at double that currently plus additions. The EC/PPM of your tap water needs to be taken into account. If your nute line recommends say 500ppm and your tap water is already 200ppm, you should only add 300ppm of nutrients for a total of 500ppm strength going into the pot.

I'll second the recommendation from @Jerseyphresh1 - Flush that pot. Mix up some light nutrient solution of maybe just the Hornet A/B at 1 or 2 ml/L and run it through. Collect the runoff and start testing the numbers for both EC and pH.

From what I've read and learned here, autoflowers like somewhere between 50-80% nutrient strength compared to photoperiod plants.

Water to runoff. Water to runoff. Water to runoff. Seems like a waste but it works. I am currently watering my coco plants 2x a day to at least 20% runoff if not a bit more. One massive gal right now is liking 1500ml in the AM and 1000ml in the PM. 2.5L per day of nutrient solution. I check my runoff #s religiously as watching volume, EC, and pH can tell you what the plant likes or does not.

Good luck and update us with some numbers.

 

[SweetTrees]

Hello guys, thanks for all the solid advice. Tried a few things but not seen a U-turn its got worse.
So ive stopped all the excessive nutrients and flushed them out using water at ph 5.8 with 1ml of coco a and 1ml of coco b.
the temperature is 27 degrees and humidity is around 25-35.
the “3rd” plant that was originally looking bad having witches finger is now better however the other two have got worse, ones almost dead completely all the leaves have shrivelled up but the bud still smells sweet,
I have a strong outtake fan and a 4inch intake fan which is less then a quarter of the strength of the outtake.

 

[DCLXVI]

Oof, yea, it may have been too late for them. Hard to undo "too much." Let them ride out their time with the reduced nutrient flow and you may get a few nice pieces.

Did you happen to catch any of the runoff water and test for ppm?

I'd say you have everything you need for a successful second run. There is a lot to learn and even if this one doesn't pull through the way you wanted, the hands on experience will be invaluable moving forward.

I think the nute line is probably fine to use and follow their chart. I would suggest mixing up a gallon of water with their advised nutrient ratios, let it stand for a bit, and then check the EC/ppm and pH. Autos like somewhere from 50-80% strength but it's hard to know where that is without starting numbers. Once mixed if it's too strong you can always dilute down with distilled water.. Going from there perhaps use only 50% of the recommended dose but a starting ppm is essential to being accurate.

Good luck!