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Help! Rust fungus or lack of Mg/Ca??
- Thread starter Vancho
- Start date
Looks like u sprayed something and that might have been to strong. I could be wrong.
Otherwise, what's your tapwater like and how much calmag do you add to it? At your plants stage I'd probably target the 120mg/L of calcium and 40mg/L of magnesium mark.
And in full flower around 150-180mg/ L calcium and 50-60 mg/L magnesium.
Thats just a rough guide..it really depends on your lights strength.
For example.. With 800w LED that won't be enough..but for 400w HPS its probably too much already.
Otherwise, what's your tapwater like and how much calmag do you add to it? At your plants stage I'd probably target the 120mg/L of calcium and 40mg/L of magnesium mark.
And in full flower around 150-180mg/ L calcium and 50-60 mg/L magnesium.
Thats just a rough guide..it really depends on your lights strength.
For example.. With 800w LED that won't be enough..but for 400w HPS its probably too much already.
I have a 60 liter tank for automatic water. Tap water is ok here, drinkable from the tap. Besides i add dechlorinating for fish. Should i use those concentration of calcium and magnesium in the 60 l tank or water the plants once a week or two manually with those ammounts?
Three Berries
Active member
They say Mg shows up first in the lower leaves. I've found Ca shows up first in the new leaves as yellowing. But not splotch like that. Starts at the tip and works in.
Maybe another trace mineral?
Maybe another trace mineral?
Get a water analysis report of your area,usually u find those online at your water supplier homepage...see what's in it excalty and adjust to what you need(3:1 ratio of cal:mag) If the problem keeps coming back its not that.
Besides that it makes sense to check leafes with a microscope for parasites.
Any other nutes used except what was mentioned before? The more info you give,the more help u can get. Thise spots could also happen if you overwater and so on.. its a complex topic. Full shot in the dark with flash makes it easier to see what the plant is really up to.
Good luck for the rest of this run,stiff
Besides that it makes sense to check leafes with a microscope for parasites.
Any other nutes used except what was mentioned before? The more info you give,the more help u can get. Thise spots could also happen if you overwater and so on.. its a complex topic. Full shot in the dark with flash makes it easier to see what the plant is really up to.
Good luck for the rest of this run,stiff
The photo above I used just a little tap water to raise the pH of the water. Only one app caused the spots on the leaves.. If you are using a complete fertilizer and using a quality potting mix there shouldn't be a nutrient deficiency. When using tap water the hydroxyl ions build up in the soil and can block receptor sites and cause bronzing or leaf spots. 
Just look it up online. You might be surprised what you find out. Sometimes u gotta do nothing, Sometimes u have to adjust with calmag. Worst case scenario would be if u need a Reverse Osmosis filter.
It might not even be the cause for your problem,but it still won't hurt to balance your water right
Interesting idea. There is some downward cupping often associated with an over feed. The one growing point I spotted as almost stopped with strong Fe signs. Some of the leaf pics look like simple burn. Others Ca. Some look strange enough to be an outside attack, but for now less feed looks best.
600w a meter of pink light might never make you happy.
It's the alkalinity that's causing the hard water spots on your plants. If you have any lockout that's the reason. Your water may be ok used at first but, after a while, the alkalinity can rise in the pot and cause water spots. One can't just add a specific nutrient and everything will be ok. You are experiencing the start of lock out
Switch waters slowly, use 75% old water mixed with 25% RO or rain water for a week then use 50/50% old with new for another week. New water without calmag will fix the problem and in 3 weeks your plants should be good.
How do i solve the problem? adding dolomite should be enough? or do i need some specific Ca:Mg ratio? yesterday i stopped watering and tomorrow i'll check the soil if its dry so the plants can intake the minerals when i water. I will test pH tomorrow, which range should i expect?
Where can i find that light related cal/mag ratio information? seems interesting
Three Berries
Active member
Get some of this. it's a wonder liquid, plant in a bottle. Calcium Chloride
bonide.com
Rot-Stop Tomato Blossom End Rot Concentrate - Bonide
BONIDE Rot-Stop® Tomato Blossom Set Spray prevents end rot in tomatoes and other vegetables. It controls calcium deficiency to prevent end rot.
bonide.com
I got these from the water suplier, cant find any Ca or Mg on the report. Sorry its in spanish
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Three Berries
Active member
Does it give a hardness value? That's usually a combo of Ca and Mg.
Three Berries
Active member
It would be carbonates?
