Rusty color on leaves

A question from a fellow grower:

Good morning,I have a question,on my plants the larger lower fan leaves seem to have what looks like rust forming on them,what would be causing this?

I’m growing in a soiless mix,happy frog,I have a 400 watt MH light,fans for fresh air and for exhaust
74 degrees and 6.5 for ph

What type of water are you using? If tap water, do you know what is in it?


Well water

Also with well water, you need to have an idea what is in it and how it will affect the conditions in your soil. Often the water can change the pH conditions in your soil, or contribute to nutrient salt build up in the soil, both of these can cause similar discoloration in the leaves.


Do you think it could be a calcium deficiency?

Nutrient salt build up in the soil, or a pH that is bad can both cause nutrient lockouts including calcium lockout. So, yes, kind of.

Finding out what your well water pH is, and even the EC/TDS/PPM would help, or better yet a actual report on what is in your well water would be the best. And also finding out what the pH is at the roots or in the soil would help.


I have her in a self watering container, will that make any difference? My waters ph is at 6.5 in the plant container

Some self watering pots might keep the soil too wet and contribute to “over watering” like symptoms.

The minerals in your tap or well water, their concentration, these could be contributing to a nutrient toxicity. Again, what is in your well water could be a big deal.


I have been using tap water but I let it sit in a open container for 48 hours before use for all the bad chemicals and minerals rise out of the water and evaporate

The Chlorine might evaporate, but the minerals do not evaporate.


If using well water do you have a water softener on it and if so are you using salt in the softener? If so you may want to reconsider, we have the above setup and Is why I I use purified bottled water so salt does not kill the ladies…

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No water softener, great clean water,my friend gave this Lady, my others that I have e are all fine

Rusty color still forming on older lower leaves,what is it?

What is the pH in your root zone? What is the pH of the well water?


Both at 6.5, what I don’t get is we have bad the mother plant for two years and no issues, same water and nutes,then all of a sudden the rust show up