Good day everyone and thank you in advance for responding to this post. I am a super newbee and built my first aeroponic system over winter vacation and am now having some issues. I bought my clones 6 days ago am now witnessing some of the plants getting brown tips and a slight yellowing of some of the leaves. The clones are Grand Daddy Purple "GDP" in rockwool cubes that sit in my 2 inch net pots with no other medium. I use Advanced Nutrients three part Grow, Micro, Bloom, and have used Sensizym once (total ppm at 410 with my water starting at 50ppm). Although the water temp first fluctuated up to about 78-80 a couple of times during the first 1-2 days, I now keep it at 65-70. The room is also very well ventilated with a constant temp of 65-70. I adjust the ph twice daily and keep it 5.7-6.1, although it did get to about 6.5 once on day 2. I have an automatic timer that waters for 1 minute every 4 minutes, as was recommended (and used at home) by my local hydro store owner. I use a 1000 watt HPS and am now running it at 18/6, but I was an idiot and ran it for about 15 hours then would run fluorescents (with no HPS) on for the rest of the night for about 5 days. The light started out at about 5 feet from the clones and over 3 days has made its way to being 14-15 inches from the middle of the bulb to the tips of the center plants. I have an inline fan at 470ish cfm that cools the hood and I have a normal fan that blows straight down my rows so that I can hold my hand under the lights and it is barley warm. My water pump is 1000 gph and have two a mister on each side of each plant (one in front and one behind). All of the root misters work perfectly. Oh, and I have never misted the tops of my babies. Nor have they gotten wet on accident. I kinda looks like the plants closest to the light have the most yellowing, but some are are just as close and don't have it. So I don't know. The picks are not great so if you need me to get back in there and do it again I will. So in conclusion I think I have problems with brown tips yellowing of leaves some weird yellow spots on a small number of leaves on about 30% of plants perhaps some droopiness diarrhea in my butt I also want to write that I have a medical cannabis card and am 100% legal. So please don't smash my door down and kill my cat.
I am not familiar completely with aero, i am growing in soil, BUT to me that looks like nute burn, are you using a feed, water, water schedule? your supposed to for soil and soiless mediums, also could be unstable ph.
Thank you very much for responding Budworthy My reservoir has 400ppm (really 350ppm after the 50ppm already in the water) of the recommended ratios by Advanced Nutrients for the veg stage. I believe that AN recommends 950ppm, but I was told by many people to do less than half of what they say. It is possible that I burned them because for the first 24 hours I was using tap water which was already at 550ppm prior to my adding the nutrients. But the water wouldn't hold the ph and I was forced to either add capfulls of acid, or buy some drinking water....so I bought the water. But I may have already done the damage. I don't think that aeroponics uses a "feed, water, water" schedule, but I am very new at this and may be totally wrong. From what I understand, aero systems use an increasing amount of nutrients at all times until the very last week of flowering when only water is used to "flush" the plants.
I have always heard do 1/4 nutes to begin with..do you know what your roots look like i am looking at a book i have and it shows a picture of leaves that look like yours do, and it says it is a result of stagnant nutrient solution and salt build up which it says will stifle the root development. It states that the salt build up is the reason for the burn on the leaves. It says a way to know is if your roots are dark and look like rotting, healthy roots are strong creamy white color. This is from the Aeroponics section of my Marijuana growers bible book! Maybe this will help, atleast i hope!! I have had a lot of help as a newb and like to try and offer what advice i can get!!
To be honest it also looks like it could be LACK of nutes. Add more nutes...Experiment and see what happens.
Thank you very much for your advice. Some of them have beautiful, white roots, but some don't really have any roots sticking out......so? I am going to change my reservoir again today after I search for a reverse osmosis system. I am also going to the bookstore to get more books with better info. Thanks again.
Thanks for the advice Budworthy regarding the book. I bought it and you're right......it is a wonderful set answers to more questions than I knew existed.