Hi. If somebody know what's going on, please let me know. I have a large autoflower in DWC. I am 16 weeks in and she doesn't want to finish, plus every 48 hrs after new nutrients, the PH drops from around 6 to below 5. This has happened for weeks now, consistently. The plant is looking fairly healthy overall, with the exception of a little heat burn on the tops (some leaves curled up and very minor fox tails). Temps were up to around 29C for a few days. I am using a 600 watt Super HPS Eye Hortilux. Temp is now around 21-25 degrees C, humidity 50%. I am using GH Micro, GH Bloom, and Dry Kool Bloom. I had the EC as high as 2.4 for early flowering, with no fluctuations , but it has slowly decreased to around 1.0. Trichomes are clear/milky and just staying there. Does not want to finish. Because of the sharp drop in PH after 48 hrs, this is my schedule. New nutrients in AM (unfortunately only about 2.6 gallons) 1-1.2 EC, then add about 1.5 litres of water in evening. Starting PH of water is 7.0 and starting PH of fresh nutrients works out to be around 6.2, so I leave it there, to start. The next morning EC around 1.0 and PH 6-6.2. I top up with about 2.5 litres of 1-1.2 EC, depending on any fluctuations. I then add water again in evening. The next morning EC will be holding around 1.0 EC, but my PH drops to around 5.0, and sometimes lower. One other note, she's drinking about 1 gallon /24hrs. Any idea why my plant doesn't not want to finish? There is no amber trichomes, and the plant is showing no signs of yellowing. Any idea why after 24hrs the PH drops hard? I could see if the strength was too high and it was drinking mostly water, the PH would drop, but that's doesn't seem to be the case here. Any input would be greatly appreciated.
Need Help. Autoflower doesn't want to finish flowering and I am getting a hard PH drop after 48 hrs
- Thread starter Layzer306
- Start date
JakStraw from Wichita
Active Member
I’d assume your using some kind of air stone or somthing in this situation, depending on what trace elements/buffers you have in the water and the co2 to O2 ratio of the water you start with... over time your ph can drop or rise from the oxygen exchange in the water. Try getting a barrel of water made up a day before and put an air stone in it so the ph can stabilize then use that as your “starting” water
Thanks for the reply. I'll try that. I just thought it was very odd from 36hrs-48hrs it all of a sudden drops hard. I wish I was using a larger reservoir. Yes, I am using an air stone. Attached is a pic of the roots.
Attachments
JakStraw from Wichita
Active Member
a larger reservoir would help reduce how fast the ph fluctuates also, larger volume of water changes slower then small volumes
JoeBlow5823
Well-Known Member
What this guy said. Let your water "settle down" for a day before you use it. I do this even with organic soil. Ph is all over the place for the first 12-24 hours especially when adding nutes. And the bigger the reservoir, the larger the "buffer" you have. With growing in soil, a plant in a 5 gallon will burn through its nutrient supply 3x faster than if it was in a 15 gallon pot.
dendroaspis
Active Member
I’ve had this happen with me a lot with GH. Problem was gone when I switched nutes and gave my tank a good rinse
I am curious, did you have problems with GH throughout your grow, or just during late flowering. I had no PH issues whatsoever, until near the end.
dendroaspis
Active Member
Always halfway during flower.. and sometimes in veg. Last weeks where ussually rather uneventfull. I used h2o2 to stabalize the ph.