Minor problems with Auto flower(deficiency?)

GixxGrows · October 23, 2020, 7:26am

My first grow went in the trash I was growing Strawberry cough, went way wrong somewhere.

This is Blue Dream Auto I have noticed some spots on my leaves I think may be Calcium deficiency. Also some leaf tip curling. I last watered mid day on Sunday it is now Tue.

As for details here it goes I have them under 20-4 lighting, temps mid 70’s, RH about 55, i have a Exhale 365 bag in there. I’m using Vegamatrix as nutes. I do a double dose for my 2 gallon water can, so basic recipe doubled for double water. I water roughly every 3 days or so trying to let them dry out a bit in between. I do pH my water to around 6 after nutes. I have AC Infinity fans and filters in and out along with oscillating fans inside.

That should be enough here are some pics. I would like to get ahead of this as I am almost mid way through their life and about to drop more beans to get a perpetual grow going.

MDBuds · October 20, 2020, 11:55pm

That definitely looks like a calcium deficiency. First time I’ve looked at photos on here and was able to tell immediately. You’ve got a good camera.

Darkheart420 · October 21, 2020, 2:37pm

What kind of medium are you using?
Are you using pH down? Up?
What is your nute pH before adjusting it?
Just trying to get a clearer picture.

Strikker · October 21, 2020, 2:59pm

I too am thinking calcium deficiency. When I see something like this I will start adding a Cal/Mag or just calcium, maybe 250 -350ppm to RO water. I will keep an eye on new growth to see if I have solved the issue or do I need to continue adding.

Good Luck

Mrb53004 · October 21, 2020, 4:00pm

Do not forget, if Mag is low, can’t absorb the calcium.

Darkheart420 · October 22, 2020, 8:33pm

I was hoping Donald would have come back and answered my questions.

There is a possibility that he doesn’t need to pH. And that his pHing low to 6.0 is locking out the plants ability to access Cal like it should. Bringing up the pH to closer to 6.5 will allow the plant to access Cal much easier.

This is if he needs to pH at all. If he has a decent medium with buffers and his water isn’t terrible he may not have to.

I really avoid pHing in buffered soil and let the soil do what it’s designed for. Constantly adding acid to your medium will lower your soil pH over time,locking out your plant.

I use Pro Mix that is buffered. My tap is at 197 ppm with an out of tap pH of 8.2. After 24 hours this drops to 7.5. After I add my nutrients my pH drops to between 6.7 -6.2 depending on the strength of my nutes. My buffers can handle the rest.
It is important that I leave my water out to off gas extra C02 so it is stable before use.

He may already be using enough Cal. The plant just can’t access it very well.

GixxGrows · October 22, 2020, 11:11pm

I am in soil I normally go over 6.0 on pH. last feeding was low. I will keep it around 6.5 i was thinking it was ok between 5.5 - 6.5.
As far as light i have a MarsHydro sp300 about 12 - 18 inches from canopy at %75 right now, 20 on 4 off.

I will def up my pH for while again thanks for the links. Reminds me when i was a moderator on a few garden (veggie) forums back in the day. Was always throwing knowledge.

MDBuds · October 23, 2020, 12:32am

@GixxGrows you’re getting hydro mixed up with soil. Hydro can go as low as 5.5 and be fine but you should still keep it between 5.8 and 6.5.

Soil on the other hand allows for best nutrient uptake between 6.2 and 6.8.

I try to keep mine around 6.5 in the sweet spot in the middle. Calcium and magnesium are more bioavailable in neutral or close to neutral soil. As you start dropping under 6.5 your plant starts losing more and more access to available calcium and magnesium.

Darkheart420 · October 23, 2020, 12:37am

I had a feeling something was off. Glad you came back.

Since you are in soil I still wonder if you need to pH your nutes. My grows improved greatly when I stopped.

Not something that you’d want to do mid grow but in the future you may want to explore it with a clone and see.

If your water isn’t too alkaline you shouldn’t have to at all.

MDBuds · October 23, 2020, 1:07am

@Darkheart420 I only measure my feedings for ph just to make sure it’s at healthy levels and I don’t adjust unless the ph is under 6.0 or over 7.0. Generally purified water or dechlorinated tap water is around 6.8 with distilled water at 7.0.

Organic nutrients are slightly acidic and can drop your ph in the nutrient mix to between 6.0 and 6.5 depending on the mix you’re using. If you’re adding micro nutrient supplements though it can bring the PH back up as most are more alkaline with the exception of things like boron and a few others. Most of the time if you mix your nutes right you won’t have to adjust ph for organic soil grows but you should still test just to be safe.

Mrb53004 · October 23, 2020, 5:08pm

MDBuds if you can, please help me with this question.
Soil - I make my own. I add Calcium Sulfate Dihydrate - Gypsum - CaSO42H2O and magnesium. Do you recommend adding lime?

MDBuds · October 23, 2020, 8:46pm

@Mrb53004 gypsum works pretty well as an additive with lime. Dolomite lime which is the most commonly used lime has high levels of magnesium but cannabis needs more calcium than magnesium so if using dolomite lime I would amend with some gypsum as well. Gypsum and magnesium alone would work well in the right ratios but I like how lime conditions the soil myself in combination with gypsum. Just have to make sure your ratios are right and that all entirely depends on how much soil you are making and what else you are putting in it.

Mrb53004 · October 23, 2020, 9:16pm

Thank you very much. I make organic soil for my garden (veggies) made from pure compost of leaves, kitchen scraps (no meat, veg only), fresh fish (trout - I catch and freeze in summer to make my compost over the winter). I pot the organic soil for my girls as follows: 1 part Soil, 1 part Black Gold Organic Sphagnum Peat Moss, .25 Organic vermiculite, .15 Organic perlite, .5-.1 cocoa, < 1% MarineLand Diamond Media Premium Activated Carbon, Blacks & Grays
For nutrients - the gypsum - not sprinkled but water fed at rate of 2 tbls per gal and only at beginning of grow. Later (2 mos) will top dress in soil. Magnesium - .5 tsp per gal of water, fed monthly and used as foliage spray, Happy Frog organic spread in soil only at beginning of grow, Triple Super Phosphate 0-46-0 (use ppm meter) during heavy veg mode, at flower (use ppm) LANGBEINITE - Sulfate of Potash Magnesia (K-MAG) Organic Fertilizer 0-0-22. Organic kelp and seaweed extract for foliar spray and water during stress times (high heat - I am in Vegas and we had +116 for almost 3 weeks, 2 weeks of plus 110).