I have two plants (one blue dream and one dutch treat) that are in weeks 2 and 4 of flowering, respectively. I have noticed a stall between both of them and looked into what the causes might be. I checked PPM of my solution and run off and are both within adequate range. When i checked the pH of my nutrient solution, it is about 6.5 (using LA City Water which is about a 7), however, when i check the runoff of both, it is sitting extremely low at around a 4.2. I bought some pH up to try and bring the pH of the runoff up to at least a 6, but after using like half a bottle (small bottle that is sold in the testing kit), it only moved maybe 0.6 up to 4.8. I then took a soil sample from the top of my pots and it measured about 7.5 after using the pH up, so now i dont know what to believe. I have pasted my grow information below and attached some pictures of the leaves (maybe its just nutrient burn but it seems like a deficiency and is being locked out due to low pH). Any advice or help is much appreciated! I already lost one of my girls to an unknown reason (dried up and withered plant in one of the pics), so i am really trying to not lose this one as well.
Indoor or outdoor? - size of grow? Outdoor
Otigin of seeds? Seeds
Regular, feminized, or autoflower? Feminized
Origin of water. PH, EC/TDS of source water? La City Water / pH 7 / TDS 250
PH and TDS/EC of if mixed solution? PH 6.5 / Feeding 3 tsp/gal of Fox Farms Tiger Bloom, 2 tsp/gal GHP KoolBloom PK Booster, 1 tsp/gal of cal mag (Fox Farms Bush Doctor once a week)
Nutrients or fertilizer system used. Feeding 3 tsp/gal of Fox Farms Tiger Bloom, 2 tsp/gal GHP KoolBloom PK Booster, 1 tsp/gal of cal mag (Fox Farms Bush Doctor once a week)
What typr of lighting are you using? LED, HID (MH, CMH, HPS), or Fluorescents? Please elaborate. N/A outdoor
What are the temps in your growspce? Day / Night? About 75- 79F during the day / 67F at night.
What is the RH = relative humidity in your growspace? Day / Night? Day: 58 - 66 / Night: 99%
AC, Humidifier, De-humidifier? None
Do you have a Ventilation system? Size? 4", 6"? NO
Co2 Yes / No? No
How long have you been growing? 3 years
What budget have you set in order to grow successfully? N/A
If you grow hydro, then please explain your hydro method. DWC, R-DWC, Ebb and Flow, Or; Other? Other? N/A
Mineral salts will build up over time and submarine your pH, making pH unmanageable. This is particularly the case when using very salty products like the FF nutrient line. I expect you have a salt buildup in your soil and need to flush to correct the runoff pH. Happy Frog will revert to a pH of ~6.5 with a good flush down to ~300 PPM.
You might consider ditching the FF nutes and going with Jacks 321. Jacks is far less salty than the FF nutrients.
Thanks for the reply! I will make sure to flush for the next few feeds and keep measuring the runoff while doing so. Ive already spent a good amount of money on the FF so ill finish those out but just use more sparingly.
Fortunately this is in the early parts of flower, so hopefully it wont affect yield too much. Only seen this issue for about a week.
Pretty big plant in not so big of pot, could be root mass breaking down and throwing ph too. Either way I think you’re correct on the flush, then reset nutrients.
Thanks again for your help guys! I started the flush today and already saw a small increase in pH level so I think this is the right move. I did have a couple other questions on what you think might be the best move.
While flushing, should I add in some pH up to try and speed it up a little? or will this be more detrimental if the problem is actually salt build up?
I know it is hard to estimate, but how long/how many feeds should i flush or do you think it might take to flush to get it back to normal? (i know this is subjective but wanted to see what you thought).
Happy frog will revert to a pH of ~6.5 with a good flush down to ~300 PPM. It’s best to use RO or distilled water, but if you don’t have those, then pHing your flushing water to ~6.5 may help.
One flush, one time. Flush it down to ~300 PPM and the problem will be solved. It will take 2x to 3x the volume of the pot to get it there. For instance, a 5 gal pot will take at least 10 gals of flush. Do not stop until you get at or near 300 PPM coming out the bottom of the pot. A flushing agent such as Sledgehammer or FloraKleen will make the process faster and it can be done with less gallons.
will do. any harm in flushing a day after i already watered? I got the message above for one big flush after i had already done my “flush” (i was planning on just normal feeding until things settle down).
No it wont… I’ve done it before. Your plant will be fine. For oerwatering it takes alot more than watering just 2 days in a row. It would take a week or so of this to be Overwatered.
Alright so the mystery continues (or maybe it is still my own ignorance). I flushed today and got the ppm down to about 330 (same ppm as the tap water i am using). The flush took care of the ppm issue and brought the color of the runoff from a cloudy yellow/green to a much clearer very light yellow. The pH of the runoff after the flush did raise a little bit to about 5, which was a good sign. The soil pH meter that i purchased showed a relatively solid pH reading (5.7 - 6.5) about 5 - 6 inches below the top of the soil. When i measure the pH toward the bottom of the soil through the pot’s drain holes, the pH is still very low (4.0 and lower). I dont know if that matters as much as the top half of the pot but i thought it would be worth noting to get your opinions.
Lastly, i fed with a half dose of FF Cal Mag, Tiger Bloom, and GH PK Booster, and the issue of the acidity came back. Maybe i do need to switch off the FF brand and go with a more mild brand as suggested above, but i thought soil was supposed to buffer acidity pretty well (especially if i am keeping it within the FF family for all products). Maybe i just need to pH up my nutrient blend when feeding so that it keeps the top half of the pot within range?
The leaves dont look too terrible and the copper/yellowing seems to have stopped, so now i am somewhat thinking that i had just given her a little too much cal/mag and thats what the issue was?
Idk i feel like im overthinking everything. What do you guys think?
