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All 4 of my plants in my flower room are all getting brown spots all over the leaves. I have done countless research and have might of came to a conclusion. Nitrogen or calcium deficiency. I do not know this for sure so in that case i would like some back up. If it is how can i fix it? I need a second opinion of diagnosis before i go about treating it.
Thank you
hi looks like Manganese deficiency to me bro,i might be wrong see if someone chimes in eh..
A magnesium deficiency, as manganese deficincies are mostly characterized by interveinal chlorosis which is a yellowing of the leaves between the veins with the veins remaining green. The browning spots is called marginal necrosis which is usually caused by a calcuim or magnesium deficiency.
A magnesium deficiency can be quickly resolved by watering with 1 tablespoon Epsom salts/gallon of water. Until you can correct nutrient lockout, try foliar feeding. That way the plants get all the nitrogen and Mg they need. The plants can be foliar fed using ½ teaspoon/quart of Epsom salts (first powdered and dissolved in some hot water). When mixing up soil, use 2 teaspoon dolomite lime per gallon of soil.
If the starting water is above 200 ppm, that is pretty hard water, that will lock out mg with all of the calcium in the water. Either add a 1/4 teaspoon per gallon of epsom salts or lime (both will effectively reduce the lockout or invest into a reverse osmosis water filter.
Mg can get locked-up by too much Ca, Cl or ammonium nitrogen. Don't overdo Mg or you'll lock up other nutrients.
Calcium deficiencies are difficult to distinguish visually as excess calcium may produce deficiencies in magnesium and potassium.
If you feel that you have a multiple micronutrient deficiency than I would recommend trying some Cal n Mag and even possibly some Microblast.
JSG.
Had the very same thing happen to me just last week.
Epsom salts, as JSG mentioned, seemed to do the trick for me.
You can see the issue I had and I took some some pics in my latest journal update here: LED Logger
I was also advised that as some leaves were too green I might have too much nitrogen in the soil. I'll just stick to watering from now until the end of bloom which will be soon.
After applying the Epsom salts the issue has stopped. All new leaves have returned to green. I might add a little more and try the foliar feeding as JSG mentioned.
Hope it turns out ok. You can get Epsom salts really cheap in any chemist.
Take care
Thank you for all your feedback you have really taken this headache of mine away. I am running ebb an flow FYI. I will try to just spraying them with the mixture stated above. Should i continue the ebb an flow or leave it off for a couple days?
I would need a lot more information about your grow before making any suggestions about modifying watering schedule. Find the troubleshooter in this forum and fill it out...there is an amazing amount of information there.
JSG.
Sorry about being too vague. My plants are in flower, i currently water once a day 15 minute flow in ebb an flow in a 4 by 2 grow tray. My plants are about 20 inches tall and are in 4 inch rockwool cubes that are surrounded by hydroton clay rocks.400W HPS. I keep my PH around 5.8 to 6.0. my temperature is a little low in my bud room. Around 45-50 degrees. Humidity i am not sure but i do have a outtake fan. The only nutrient i use is Maxibloom, i put 4 tsp in my 20 gallon reservoir. I only put about 6 gallons of tap water in the resevour because it is all i need. I am going to start watering up to 3 times a day once the roots expand a little more. I feel as if the rock wool soaks up too much water. After reading this does anyone know what these brown spots are? I am desperate to fix it and help my ladies grow as healthy as possible.
Did you not see my post. I think your issue is a magnesium deficiency.
You need to get some Epsom salts and mix a tablespoon with a gallon of water.
Crush the salt in a cup and add hot water first to break it down. If the plants dont respond quick enough just add another feed of it.
I hope this helps