Hello, I'm on my first grow...soil. Already had to flush due to nute burn. Been on 18/6 for two months and everything has been going fine for the last three weeks. Then, two days ago, some of the fan leaves turned yellow overnight with dark spots and started shriveling upwards. Several have died and/or fallen off in the last two days. I've checked the threads on diagnosing problems and I'm thinking I have a phosphorous deficiency. Can anyone confirm if that's the case? This is my first post so I hope the posted pics show up. I've started adding Foxfarm big bloom to my watering regiment and added some Foxfarm Tiger Bloom to the water today. I was going to go to 12/12 this weekend. Should I postpone that? Thanks a ton.
Very good yes phosphorus def stay in veg till she is healthy again,To rule out PH related issues complete a soil runoff PH test....... you need PH test equipment, chemical PH test or digital PH meter also PHup & Down Correcting Solutions....for emergency you can use vinegar to go down and baking soda to correct up.... with PH corrected water (6.5-6.8PH ) pour enough water in the pots so the water runs out the bottom of the pot ...test the PH of this water.... If the PH reading is out of optimum range 6.5-6.8 PH, you need to flush your plant. Flush with PH corrected water, till in optimum PH range, 3 times the volume of the pots rule of thumb but may require much more flushing if the rootball is thick & sour EG: 1 gal pot = 3 gal. flush add 1/2 strength nutes to the last gallon of the flush.
Thank you for the response. I should have mentioned that I have a PH meter and since the last flush, the PH has stayed at just below 7. I've been checking it daily. I have also purchased PH Up and Down so I'm ready for that as soon as it's needed. How do I know when the plants are healthy again? I've read that the leaves that have turned color and shriveled won't go back. Do I just wait a few days or weeks and make sure that all new growth and/or the leaves that haven't changed don't change color? Do I still need to flush or can I just add nutes and wait for the plants to perk up? I also have a question on how to use PH Up and Down. Here is my assumption on how to use it. Say the PH of my soil is 5, then I need to bump it up a couple of points. If the PH of my water is 7, do I add PH Up to the water a little bit at a time, stir it up, and keep testing until the PH of the water is around 9? Then, water the plants with the PH adjusted water and wait a day and check the PH of the soil again? Repeat the process until the soil PH is in the correct range. Am I correct with this assumption?
if your ph is in optimum range & apparently it is then they just need feeding as to when its healthy again ...your correct the damaged leaves do not repair them selves, ....remove the damged leaves so that you are assured the defenciey has been halted, once you see no further leaf damge your on the road to recovery use your PH corrector to adjust everything , water, ferts, flush, in optimum PH range EG: mix the ferts test the ph and correct as required correct your water to optimum PH range before watering....do 5 gallon buckets in advance etc etc etc if your water PH is 7.0 add a few drops of PH down stir well take a reading, keep adjusting till your 6.5-6.8 PH hope that helps
OK, that's good to know that I should adjust the PH for everything before I add it to the soil, but I'm still confused on how to correct a PH problem in the soil. If the PH of my soil is 5, do I want to use water with a PH close to 9 to get it back to the 6.8 range? Is that going overboard?
just pour 6.6PH in untill the outgoing runoff remains 6.6PH is ideal if your soil 4.0 and you used 8.0 to meet in the middle of 6.0 this would work, however we have the distinct possiblility of new symptoms of leaf spotting from wild PH swings this doesnt always happen but often enough, I confess when I have an acidic rootball I use the garden hose which which is generally 7.1 ....it causes me no issues but I know my strains in a nutshell just pour 6.6PH in untill the outgoing runoff remains 6.6PH is safest & optimum