Purple Stems and Veins + Other Issues

So let me start by giving details of my grow. Temps are 76F-79F and humidity is 55%- 65%My plants are in week 4 of veg and I have been running Mills Base A+B, Elite 91 Silicic Acid, and Elite 91 Roots.

Npk values are as follows:

Mills Nutrients
Base A: 3-0-1
Base B: 0-4-3

Elite 91
Silicic Acid: 0-2-1
Roots: 1-0-0

I have been feeding per Mills light regimen and the past two feedings have been as follows:
Mills Base A+B: 6ml/gal
Elite 91 Silicic Acid + Roots 0.5ml/gal

I am using RO WATER.

Now per Mills they claim that no calmag products are needed with their nutrient line which I’m wary of.

So my total Npk values are : 4-6-5

Nitrogen is too low I’m realizing now and it is because I did not realize with the Mills line you HAD TO have the complete 5 bottle lineup so I decided to leave out Start-R and that seems like it was a mistake. That is where most the N comes from I am now realizing being that it sits at 5-0-0.5

So with that said I ordered some and it will be here tomorrow!!

I have quite a bit of droop going with my plants as well as purple stems and purple veins. It is not due to drying out soil as the soil has not dried out.

Also the yellowing looks to be probably Nitrogen Def and the rust colored spots possibly Calmag???

Please let me know your guys opinions as it would be very very much appreciated and welcomed!

I will be receiving the Start-R tomorrow by Mills and I am hoping this will shape things up and balance my plants health back out but am still unsure of the purple veins and stems as I have read it could possibly be Cal Mag def?? What do you guys think!?!!

This post shows what I believe to be a Nitrogen def and possibly CalMag def as well...What do you guys think... Any suggestions and input greatly appreciated!

Forgot to mention I'm growing in Fox Farm Ocean Forest soil in 1 gal pots currently. Also forgot to list ph, ppm etc.


Nutrient Solution in @

PH 6.5
460 PPM




Runoff Out @
PH 6.1
975 PPM


I water till about 20% runoff to ideally flush out excess salts.

The purple stems and veins showing at the temps you are running would not be from temperatures too low. Magnesium deficiency is most likely the cause. The yellowing (chlorotic) leaves are another sign.

buzzmobile said:

The purple stems and veins showing at the temps you are running would not be from temperatures too low. Magnesium deficiency is most likely the cause. The yellowing (chlorotic) leaves are another sign.

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Thanks for the feedback buddy


I will give them a boost of Mg today and see how they react.. Many thanks

I’m thinking after reading on Epsom salt that 1/2 tsp per gallon added to my normal feeding regimen should do the trick.... we shall see

Start with 1/2 tsp per gallon and see how it goes.

buzzmobile said:

Start with 1/2 tsp per gallon and see how it goes.

Click to expand...

Done and Done... we'll see how they respond over thr next few days to it and I will be back with an update for yah

I have used Mills your supposed to use Mills a & b with start. At 10ml each in 10lt. Mills have brought out cal mag for use in soft water.
Tbh my water is Ec0.2 but didn't need cal mag
All the best with your grow

IronLionZion22 said:

Npk values are as follows:

Mills Nutrients
Base A: 3-0-1
Base B: 0-4-3

Elite 91
Silicic Acid: 0-2-1
Roots: 1-0-0

I have been feeding per Mills light regimen and the past two feedings have been as follows:
Mills Base A+B: 6ml/gal
Elite 91 Silicic Acid + Roots 0.5ml/gal

I am using RO WATER.

Now per Mills they claim that no calmag products are needed with their nutrient line which I’m wary of.

So my total Npk values are : 4-6-5

Nitrogen is too low I’m realizing now and it is because I did not realize with the Mills line you HAD TO have the complete 5 bottle lineup so I decided to leave out Start-R and that seems like it was a mistake. That is where most the N comes from I am now realizing being that it sits at 5-0-0.5

So with that said I ordered some and it will be here tomorrow!!

I have quite a bit of droop going with my plants as well as purple stems and purple veins. It is not due to drying out soil as the soil has not dried out.

Also the yellowing looks to be probably Nitrogen Def and the rust colored spots possibly Calmag???

Please let me know your guys opinions as it would be very very much appreciated and welcomed!

I will be receiving the Start-R tomorrow by Mills and I am hoping this will shape things up and balance my plants health back out but am still unsure of the purple veins and stems as I have read it could possibly be Cal Mag def?? What do you guys think!?!!

Click to expand...

There is not much more wrong with the plants than can be expected, so you're basically doing most things right.

- The plants show I think a combination of Mg deficiency and P deficiency

The Mg comes with flowering and so to does the P deficiency.

RO water means magnesium and calcium are filtered out of the tapwater.

The way I solved it when I was still using RO water, was to put a pinch of magnesium lime in a quart of RO water, and after a day filter pour off the clean water and add 3 quarts of RO. This was enough to stop Mg deficiency. This is just for restoring minerals to the water itself.

During flowering, you need extra Mg, so 0.1 EC of epsom salt will help. With RO water the magnesium deficiency already starts with the first pre-flowers, at the 8th or 9th mode.

- The real cause beyond R/O water and flowering, the 1 gallon pots

A big root system can take up much more nutrients than a small system, especially when it is healthy. That means you can use lower nutrient concentrations, which also helps with the taste of the finished product and saves money.

You should use 1 gallon per expected foot of growth - 5 foot plant, 5 gallon pots, if you want to avoid nutrient deficiencies in soil. Even if you prune the plant to be 3 feet, you still want a 5 gallon pot.

- pH is too low

Right now the plant wants to take up a lot of P, K and Mg, and those are best taken up at a higher pH, closer to 7.0.

When you have the yield you want and switch to the maturation phase of growing, you'll want to drop the pH to 5.5-6.0, to allow for micro-nutrients to be absorbed better, and facilitate more fungi.

- What to do

- amend the RO water with magnesium lime
- repot into large pots
- add a few tablespoons of magnesium lime to the FF soil, wet thoroughly and let it rest as long as possible before use.
- as first feed after repotting, you may want to use the Base B: 0-4-3 or a high P/K nutrient at 0.4 EC or and 0.1 EC of epsom salt (MgSO4). The P will encourage root growth more than root stimulators do.


Otherwise, everything seems ok. They're just at the edge of flowering, with RO water and small pots.

is not due to drying out soil as the soil has not dried out.


Let the soil dry out

Mattbho said:

is not due to drying out soil as the soil has not dried out.


Let the soil dry out

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I didn't quite put that the right way.. The soil has definitely been getting to the dry point so no worries there. Not keeping the soil to wet forsure but thanks for the heads up there