Need advice Calcium deficiency?

Hey guy’s second time grower here trying to diagnose the issue in the picture.
I think its calcium deficiency but not a 100% sure.
Grow info:
Supersoil Mix / NLS mix in the bottom 1/3rd of container.

5 gallon fabric pots.

Water every 3 days with 3/4 gallon per plant.
Water at 6.5 PH RO water and 20% tap water with 2ml Cal-Mag. PPM is usually between 60 and 70 ppm.

Lights on 18/6
x1 450w Mars Hydro TS 3000
x1 600w LED

4x8 tent

Current temp during flower
Lights on 76-80f RH 50-55%
Lights off 68-72 RH 45-50%

Plant in question is Bruce Banner Autoflower currently in week 2 of flower.
Seems to be affecting the old growth first nothing on the newest growth. Bruce Banner has had younger leaves claw on and off for the last week or so. Plants were watered at the time of pictures.

Any help would be appreciated.


I had a similar problem that looked a lot like yours with my last BB. I was not getting results from cal/mag. During this time I ordered a nutrient kit from Mills for a hydro grow. I emailed them about adding calcium to their nutrient schedule, and below is a copy of their reply. Since they described exactly what I was going through. I started feeding the problem plant the Mills nutrients, and it quickly fixed the problems. The plants never showed any signs of deficiency until flushing. Your fastest way to get on track maybe a good complete nutrient schedule.

With Mills, Basis A has calcium and Basis B has magnesium, so adding additional calcium or magnesium shouldn’t be necessary, even if you’re using RO water and/or growing in coco.
Since the nutrients are already in balance, if you do start seeing signs of calcium or magnesium deficiencies (or the plant just starts to look a little hungry overall), we recommend just raising the Basis A&B (in equal amounts) by a few ml/gal while keeping everything else as-is instead of adding a calmag additive.
This is because we find that usually what happens is that plants tend to show signs of a calcium or magnesium deficiency before other deficiencies. So if you use CalMag, you treat the calcium deficiency, but are more likely to see other deficiencies start to pop up. So what happens is you end up playing whack-a-mole going from one deficiency to the next, when really they just need a little more of everything. Because of this, we recommend adjusting the Basis A&B as necessary to keep them dialed in instead of calmag.

Hope this helps, if you have any other questions, just let me know.


Thanks for the reply!

@elementhc, from your pictures it looks like you have a calcium, magnesium, and phosphorus deficiencies.
Let’s see if we can get another option, @PurpNGold74 what do you think?
I remember you had a very good explanation of deficiencies and how they appear.

1 Like

@elementhc, Sorry about the lack of responses to your question. How are your plants doing? Do you still need some more options about your plant’s issues?

Dont worry about it bud, thanks for checking. The plant is still the same I raised the calmag to 4 ml per gallon and I will add some molasses on next few waterings and go from there. The plant was top dressed 12 days ago with 3-9-4.

1 Like

Hey @beachglass do you know any forum members that can help out @elementhc?

1 Like

@elementhc What nutes are you feeding? Your ppm is low. The leaves on bottom portion of plant gets yellow and fall off because the ladies have depleted what they need from them.

I am in Supersoil mix growing organic with dry amendments and bottom 1/3 of the pots is a Natures living soil mix. I have top dressed the plants almost 2 weeks ago with 3-9-4 flower girl fertilizer and some worm castings.
I know the dry amendments take a few weeks to actually break down.

Im thinking my only option right now would be to make a compost tea for a quick boost of nutrition. I have to find a good recipe for flowering tea.
Thinking of using below but not sure if i should add any 3-9-4 fertilizer in the brew:

x2 cups Compost/guano high in phosphorus and potassium
x1 cup ewc
x1 tbsp kelp
120mg of blackstrap molasses

I am open to any suggestions.
Thanks in advance.

1 Like

Tagging a few organic growers, i think
@JaneQP @MeEasy @skydiver @HippieRunner1

1 Like

Thanks alot for taking your time and trying to help. I appreciate you.

I would also go with a tea with some cal/mag in the mix.

Thanks for the tag @beachglass :grin: hi Element 60 70 ppm is that after the calmag? That seems low, I have tap water that is 600 ppm so I to mix it 50/50 with ro to bring it down to 300. I’ve asked my nutrients guy (Earth Dust) about using low ppm water and this :point_down: was what he said. I’m thinking the nutrients he mentions in Dust is something you can look into, whether your mix has it or maybe you can add them eliminating the use of calmag because it can build up in your soil and have a opposite effect. Hope this helps you out, good luck

:point_down: copy paste from the email :point_down:


The components with the most Calcium and Magnesium in Earth Dust are Azomite and Limestone.

We are dependent on the microbiome to break down the amended nutrients and get them bioavailable for the plant at a rate that will keep up with with the plants demand for nutrients. If you find that the plants demand is higher than what is immediately available in the medium, additional supplementation may be required.

This is why the “cooking” process is so important. The more time you are able to allow your medium to cook prior to transplanting, the more the microbes will have had time to do their work and the plant will have more bioavailable nutrients at its disposal out of the gate.

We have found that the plants need more available Magnesium than Calcium. Especially the last few weeks of veg and first three weeks of flowering.

Calcium demand is highest at the third week of flowering when the plant is in its stretch phase and the amount of building blocks for cell production is at its peak.

Some Calcium and Magnesium supplements have been highly acidified. Our grow team prefers to foliar spray the additional supplementation when it is required. A micronized Calcium/ Magnesium supplement works best for foliar applications.

Are you using an RO filter. I’m curious why you TDS is so low…

We look forward to hearing back from you.

Have a great day,


1 Like

Im sorry I should have mentioned i use RO water with 20% tap mixed to stabilize the PH. After adding 2-3ml of calmag per gallon the water comes out to be 60 to 80 ppm.

1 Like

Don’t take this wrong I’m not saying what you are doing is wrong I know a lot of growers that are ph’ing and using calmag successfully. I’m just sharing the way I do it to give you another option to think about. Anyone reading this this is for organic soil growing only and I really don’t think it is a good idea for anyone using synthetic nutes

I don’t worry with ph with mine I haven’t even tested it in a year. Just my opinion I think you would be better off just using your tap water with a simple inline charcoal filter. Here’s what my nutrient supplier recommends for watering

It also sounds like your TDS meter is not giving you correct readings.
This is the calibration solution that came with my meter but it is for us/cm. I would think you could get a solution for a TDS scale meter. You may want to get a new meter with calibration solutions included. That is the only way I buy meters anymore.

Add some epsom salt (magnesium and sulphur) to your next watering maybe 1-2 Tsp per gallon and make sure it dissolved before applying.
I stopped checking Ppm and PH a long time ago as I realized all that stuff was needed when growing chemically with watering to run off and all that.
Also can use ground up egg shells and soak them in white vinegar until bubbling stops. Taste it and when ready shouldn’t really taste vinegary. If needed add more egg shell powder or vinegar. Quick way to boost calcium.
Living soil with a healthy critter population is self regulating and will adjust things as needed as long as those nutrients are in/on the soil for them to eat and then digest and poop out plant available sources for the plants roots and the mycelium.

I do check Ppm and ph if I’ve ran into issues just to get an idea of what’s happening but isn’t something I do anymore than that.

One thing to keep in mind is that some will suggest things to do but it’s based on chemical growing and not organic. Really two different approaches etc.

Hope this helps some
Many posts on my last worm poo grows
Absolutely brew a tea and use that to water. I would do this about every 1-2 weeks during the grow.


Ppm isn’t low due to your mix as RO water should be around 5-10ppm

This is great info, would you recommend me staying with the Ro water until the end or switch to carbon inline only?
Also this is the tea Im doing tonight does this sound okay?
2/3 cup Peruvian Seabird Guano
2/3 cup Earth Worm Castings
2/3 cup High P Guano (Indonesian or Jamaican)

Mix with water @ 2 cups of dry mix into 5 gallons of water to make the tea.

To that 5 gallons of tea add:
5 tbs. Maxicrop or Liquid seaweed.
5 tsp. Black Strap Molasses

This is by no means my recepie just something I keep seeing all over the forums. I still have time to pitch it if need be.


Late to the party but it looks like some organic growers have offered sage advice!

I would say 90% of my plants need nothing extra but there is the one every grow that needs a little more something than the others.

1 Like