I think my soil's pH has become too acidic and is locking out Mg....I need help confirming my issue and how to fix it. 3 gallon pots Roots Organics Soil Lucas Formula 0-8-16 GH Flora Series -50% solution fed everyday 1/4gal each plant -each week "flush" with 1 gallon plain water -all feeding/watering pH 6.5 - 7.0 If my pH is too low and locking out Mg, is the best solution to continually flush with a higher pH water until the runoff is at 6.5? Example: For 3gal pots -- flush with 6gal pH 7.0 plain water? Or should I make the water's pH higher, say 10.0? Or keep it at 7.0 and keep flushing over and over until it raises? If I'm able to adjust my soil's pH to 6.5, should I feed nutes on the last flush or wait for the soil to dry before feeding again? Should I put in some Epsom Salt in the last flush (or first feeding) or will my nute solution will be enough to combat the Mg deficiency? I posted more pics and info at my journal I appreciate any feedback!
Get a soil test kit and see... This is a pic I found....and I'll be....I was locking out magnesium... from Grow Marijuana FAQ, Cannabis cultivation - marijuana growing tips & photos
I have a digital pH pen that I've tested my runoff pH and it is too low. I am almost certain Mg is being locked out. I was more interested in how to correct the soil pH, what is the best strategy? Most details are vague such as "running x2 the amount of water as the size of pot" but I hardly hear of what the pH should be of the water using to flush. Should I adjust the water to 10 pH and keep flushing until corrected? Or flush with a lower pH like 7.0 and keep flushing until it's corrected? At the end of flushing, IF the pH is corrected, do you feed them on the last "flush" to put nutes back in the soil since they've prob all been flushed away? Or do you wait to feed until the soil has dried? Also, since I'm having a Mg def but it's caused by pH, once the pH is corrected, should I add Epsom Salt or just resume normal feeding and let Mg absorb normally? ICMAG has a good Sick Plant Guide and a picture similar to my issue
I appreciate the input but I think adding dolomite lime and such is for soil preparation...if you were making your own organic soil mixture. Dolomite takes weeks if not months to balance out as noted in your link: Garden beds should be prepared a month before planting to allow soil chemistry to achieve a balance. Although it takes several weeks to have an effect, it is longer acting than other sources of lime I know Epsom Salt is a very fast acting way to add Mg but I want to know if I even need to use any if I just solve the pH lockout....or maybe I need some to boost the Mg back up?
Do this, please. Get a soil test kit, and check your soil ph, start there. Once you know the PH, then you can properly asses. The reason why, if your are locked out, you can add as much Mg as you want, plant isn't able to use it...PH is key...
I had the same problem, this is how I fixed it. I straight up added a scoop of wood ash from my wood stove every 3rd feeding for just over a week. it brought the ph up to where it should have been, and my soil was HOT, like under 5.0 hot. Its a clean, natural method that doesnt require going to the store. (if you have a wood stove that is ) EDIT: Also, get some CalMag! Works better than epsom salts imo, I've used both. And often if your lacking mag, youre lacking cal. Common from waterting with low ppm water (RO, distilled etc)
Hi there, if it was a Mg def the veins in the leaves would still be green but in your pic there not.. looks like N def or Ph problems... Here a link to my thread when i had a Mg def.. thanks to AskEd he kept me on the right track...http://forum.grasscity.com/sick-plants-problems/687746-help-n-mg-s-deficiency-2.html
I didn't want to fill my first post with a page of pictures, I have more at my journal. Here's some other pics that makes me think it was the classic Mg def, with the green veins and yellow leaf. Does this look more like Mg def? The leaves this morning are getting more yellow starting from the tips and moving in, and veins look green. EDIT: the first pic, looking in the lower left, this leaf looks like Mg def, yA? Again, I want to flush my soil with higher pH water to raise the soil pH... What should the pH be of the water I use to flush? Real high like 10.0? Or less dramatic like 7.0 and just keep flushing? I'm testing my runoff with a digital pH pen. I would like to try the woodash but I don't have a wood stove nor do I know anyone in Socal haha. Most fireplaces in apts. are fake/gas power.
intervainial chlorosis, where the in between the veins are yellowing point to nitrogen deficiency, which may be caused by low ph which you said you had determined to be an issue. bring the ph up and you should see a rebound in the new growth. to bring the ph up if it is really low is do basically do what you said. water with water that is higher in ph then you normally are, if you spike the ph up and down constantly they will die on you cause too many nute are being locked out from the stress. you dont have to "flush" per say to bring it up but i could be a faster solution, if my ph is low i usually adjust the water pre watering to a higher ph level i would say double the differnece in ph.... sorry thats confusing example: if run off is 5.0 and ideal is 6.5 the range there is 1.5, so i would make my water 3.0 higher than 5.0 which equals 8.0. try that and see if it turns around. look for new growth in one to two days, being as when low on N new growth slows and can become stunted.
As soon as i come to a conclusion I take action. If it was me I would know that the environment inside the pots is not prime. Most likely the ph is locking out nutes, rarely does this manifest itself as one specific ailment. I would flush with ro or tap water thouroughly. It cannot hurt, it will only reestablish the correct environment through out your pots. If you just water with ph'd water then you run the risk of pockets of soil still maintaining the low ph. Flush em and who cares they will be happy to just drink some water for 2 or 3 days, and it will bring them back. I concur on the way to establish the ph 8.0 water. But if you are gonna flush thouroughly and your run off is 5.0 you might go with 7.5 ph water b/c more flushing will better establish your new ph. I believe flushing is a better option than just keeping on schedule andwatering with higher ph solution. imo
your method is definatly sound i was just more suggesting a solution to a problem that first presents itself,not one that has been a constant battle, if it is major problem that is persistant then yes i would suggest flushing. the only reason i said it that way was because the way i read the OP i took to mean that this just presented itself in the recent days past. but in short you are correct flushing wont do the plant any harm in the long run, and if that is the route you take then yes the water should be more around 7.5 so as not to spike high in the end.
I definitely can gather you are a knowledgable grower and didn't mean to step on your toes. What setup do you use?
see, really im not, im a noob in comparison to some people ive had help from. i just did my research, and i definatly didnt think that you were stepping on any toes, we are all here for pretty much the same reason..... to expand the mind in more ways then one.
I thank each of you for contributing. Diagnosis is always tough b/c conditions always vary and there are usually more than one solution to fix them. Plan of Action Flush with pH 7.5 plain RO....6gallons for each 3gallon pot, or less if the runoff gets to 6.5 When they dry up from that I'm going to add some cal-mag+ to the next feeding. Sound good?
if you are going to add the cal mag to the mix i would probably add it at the end of the flush so you dont make the plants wait till the next watering. as in... reserve the last quart of water or so and disolve it in that then give it to the plants.
I wanted to do his exactly but I decided not to add anything in the end. The reason is after flushing almost 6gal thru each 3gal pot the runoff never changed. First runoff read 5.8 for Little Girl and 5.6 for Big Sis. The runoff was the same pH after flushing with pH 8.0 water. After that I didn't have any more RO water made and the lights were going off in an hour so I just left it. I hope they'll be ok esp. cause I'm not gonna be here to watch them. Going to visit family for thanksgiving for 2 days But thank you for all the sound advice. Much appreciated friend
hey havnt check on all the threads ive posted in a while. also, honestly im still new at this too, just really getting the swing of things right now im running a cfl set up in a 2x2x5 box for flower and a rubber maid box for clones and veg. and my toes feel fine, we are all here for the same reason most times, im just trying to help and i could be wrong sometimes. but what can ya do peace