Hello everyone. Im new here and have been reading a ron of the posts on here to try to figure this out.
Growing 3 different strains at the moment. I know this was a bad idea in its self. 2 are looking beautiful and one is starting to not look to hot. Ive been getting these spots for about 2 weeks now.
At first i thought rust but nothing comes off with a paper towel. Now im thinking cal mag deficiency. I went ahead two days ago and did a double dose of cal mag with normal nutrients.
Soil grow fox farm
â—ŹSoil grow-fox farm happy frog 5 gal fabric pot
â—ŹNutrients- fox farm dirty dozen minus the folier spray
â—ŹSoil ph is sitting at 5.9
â—ŹWatering 2 times a week with one gallon of filtered water and 3/4 nutrients PHing between 6.3 and 6.4.
â—ŹLighting is vivosun folding 200w led full spectrum set to flower 80%
● Temp 68° to 72° with humidity sitting between 53% to 56% vpd 1.0 to 1.3
There has to be something i am missing but i just dont know what. Any help will be appreciated.
I think once you get the ph up a little, she’ll improve. Be careful with the cal mag. If calcium is too high in the soil and locked out due to ph then you’ll run into a potassium deficiency down the road.
Thanks so much for your help. Going to give just water and cal mag tomorrow PHed at 6.8 to 6.9 and check run off and soil ph again and see how she reacts
Welcome to the community you have already received sound advice from great growers. They are always quick to help a fellow grower become more knowledgeable and successful. Good luck my friend.
Are you getting 20-30% run off and testing the PH and PPMs? FF fertilizer is notoriously salt heavy and not feeding or watering to run off can lead to these salts accumulating in the root zone eventually tanking the PH and preventing nutrient uptake…lock out
You got some really solid advice from everyone here!!
Mix your nutrient solution like you would normally at a ph of 6.5 but double the amount of water. Soak her really really good to good runoff.
This will help flush salt build up and accumulation of nutrients in the soil.
Cannabis is so Calcium/Magnesium hungry and there are a lot of growers who overlook this.
I advise both online and off and Ca is THE most common deficiency that I troubleshoot.
Always use a Ca Mg supplement with any base. The only exception to this that I know about is Athena Pro Line, and even then its good to have some on hand.
Calcium and magnesium are also the largest (on a molecular level) elements plant need and it’s well known plants have a very very hard time up taking calcium. Do you think it’s more of an availability problem we see?
Overdoing calcium can cause huge problems with lockouts of soo many other minerals, even those it’s used in such high quantities it’s considered a secondary macro.
Nice info!
Certainly worth monitoring pH and PPM for excess salts, or imbalances that might imped uptake.
I so rarely see an abundance of Ca or Mg, and when I do its in living soil beds with little to no runoff, so runoff is key in flushing those excess salts, but again that is usually to manage base NPK [particularly P].
If it was uptake generally there would be signs of other nutrient deficiencies showing as well. These plants hold a healthy green.
No problem,
I don’t mean to dilute this fellows thread but it is relevant.
A Ca Mg supplement is recommended for all mediums used for *hydroponic cannabis cultivation, with the exception of living soil that is heavily amended with slow release sources of Ca Mg.
*Hydroponics can include the use of potted peat based mediums, aka. Promix HP, Sunshine4, etc.
Separately measuring base nutrient input and additive input is a great technique for control.
Generally I see about 100-200PPM Ca Mg for standard feed, and 200-300PPM for a recovering plant in need.
