Need help diagnosing a problem with my plants. They are 2 weeks old. Blue Mystic (Nirvana) under six, 23watt 6500k CFLs inside of solo cups with Fox Farm happy frog and 30% perlite. Brown spots on older growth. I think it may be a Ph issue, but I couldn't find anything similar to it anywhere else. I tested the Ph of my runoff and it was around 6.0. I tested the soil and it was a 5.5 so I started watering with Ph 7.0 water, instead of 6.3 which is what i normally would use. I have not given them any nutrients yet. I was planning on topping them in a week and cloning the tops. I want to do a micro SOG so hopefully I'd have some ladies and could make a banzai mother. Anyway, If anyone could help me I would really appreciate it. The plants are still growing vigorously and the new growth is healthy. It is just on the older growth that the brown spots appear.
No no you HAVE given them nutrients. What is the npk of fox farm happy frog? I dont know what bag you have as they have a few different ones out but every time you water that plant she is getting nutrients out of the soil. I dont grow soil anymore and never used fox farm just MG organic mix then promix then to hydro but I would bet you can grow that plant in that soil with only water and it'll get whatever it needs from the soil. If you see some yellowing then you can come on with a little fertilizer. A underfed plant will usually consume the extra energy needed from the lower fan leaves, it is usually a broad yellowing over the whole leaf or leafs and not spotty or localized which is usually caused from high nutrient doses. This or after taking a double look I ask are you spraying the plants under the lights? I would bet its from the nutes in the soil and accommodated by hard tap water. Do you know the ppm of your tap and what kind of water are you using? Tap, city, reverse osmosis, distilled, spring?
temps are between 65 and 80 and I don't have a humidity gauge or anything but it has pretty good air circulation and I have a bowl of water in there to keep the humidity up. I have a fan blowing over the tops of the plants and have holes drilled in the back of the cabinet to allow fresh air into the cabinet.
Fox Farm Happy Frog does not have a lot of nutrients or anything like that in there. The Ocean Forest has a lot of stuff, enough to supply nutrients for a month or so of growing.the Happy Frog is a lot lighter it is better for seedlings, which is why I used it. I think it may be a nutrient difficiency because the Happy Frog does not have as many nutrients as the Ocean Forest does. I use tap water that has been through a Brita water filter and let sit out for 24 hours to allow the chlorine to evaporate, if there is any. I test my water and it is not hard or anything like that.
I tested the soil PH today and it was around 7.0. I guess that is kinda high, and I have had this problem with the soil PH before. Earlier it was too low, and that's when I started watering with a higher PH water, but I guess it got too high. If anyone else has any clue what it might be, please let me know, if not, I am pretty sure I just need to get my ph under control, probably should invest in a better tester. right now i'm just using the caplets that change the color of water when mixed with soil.
A brita filter lowered my ppm by about 25-50ppm. It did little to help and was ridiculously slow. I am telling you its from the low rh and nutes in the soil but hey what do I know I've only been growing 7 yrs and you seem to have known the answer all along...ph and fyi 7 in soil is fine also fyi soil ph dropping is another sign of over feeding. Its not deficient I have grown plants up to 3 weeks with no nutes only ro water and they looked healthy. I remember reading that a seed has enough stored nutrients to grow fine for quite some time, just how long I cant remember but it was weeks or more I know. sorry I am unsubbed. All I have to say is good luck to you with your ph adjusting.
Look man I appreciate your advice and I acknowledge you probably know a whole lot more than me, which is why I do take your advice seriously. What I said though was that I have not fed my plants anything. The soil is fox farm happy frog, and plenty of people start their seeds in it and do not have problems. I think the only thing in it is like bat quano, and worm castings. Earlier you were saying it wasn't deficient and that the nutrients in the soil would be enough to support a plant for 3 weeks. I do not think that it would cause any problems. I test for the ppm and it is in an acceptable range. Just for the hell of it i tested the unfiltered water and the ppm was about 100 higher and the ph was much higher. I know that hydro is probably a lot better than soil, but i can't do a hydro grow so i'm stuck with soil. I envy you for being able to do a grow that complex, but in the meantime i am making due with what I can. The soil andthe nutrients in it could be a possibility, and I understand your reasoning behind thinking that, but I just don't think mine would be any different if my water is at acceptable levels and I am not feeding it, compared to several grows I've looked at on the internet and previous experience I have with the soil.
They look fine bud, maybe get the humidity up a little if you can. I'm betting rh is around 10-15% try to get her up to 40-50%. If that doesn't seem to stop it then try giving them maybe 1/4 strength nutes the next time you water and see what they do.
I'll up the humidity, good call. They are looking much better though, problem has stopped and they're all doing great. Gonna top next week, clone the tops, and find out exactly how many ladies i've got.