Ppm during flowering

4x2 tent
2 1000 watt spider farm leds
5 gallon fabric pot
Fox farm ocean forest soil
Strain: GDP autoflower
Planted: Jan 3rd
Temp: 72-77
Humidity: 50%
Last ph/ppm/ec: 6.2ph 890ppm 1.6ec

My question is about watering and nutrients during flowering. I have been adding nutrients everyday, but before I add the nutrients I flush a gallon of ph’d tap water 250ppm/.3 ec before watering with a gallon of nutrient water (typically 15ml of fox farm tiger bloom with 5ml bush Doctor cal-mad every other day usually around 800ppm). I do this to to keep my ec in range(is this a good practice?) because a couple of weeks ago I added to many nutrients and found my ec to be at 5 so flushed with 5 gallons distilled water and add nutrients to get it back to normal. This last watering when I did my initial flush with tap water add I got a runoff reading of 500ppm .6ec. I then added 1200ppm 2.5ec nutrient water and my runoff was 890ppm/1.6ec. Is this a good level of nutes fox farm schedule shows 1500ppm for week 9? The pots are dry every morning so she’s using all the water. I don’t typically let them get completely dry because of how close the light is currently (almost 12in) which I can not move any higher. I tied down the top of the plant to try and keep it down and I can not do anything to move them further away. I’m not sure if this is light burn or nute burn, and I feel like I should be giving her more nutes? All of the tips looked fried which made me think nute burn but it could also be the lights? If it’s lights, should I bump up ppm to 1500 like the nute schedule says?


:point_up_2: soil likes a wet to dry cycle and depending on the vessel size this can be 3-5 days. Feeding to approximately 20% run off on feed days is all it takes to rinse the salts from the previous feeding that may have accumulated in the root zone. Girls look super healthy though :love_you_gesture: FF does require the periodic flushing as recommended


You don’t want to water every day when in soil. You’ll get the best root health by allowing the soil to dry out between waterings.

Be sure you are feeding a balanced nutrient mix. Big Bloom and Grow Big are required throughout the grow cycle.

Maintain a runoff PPM of 1,000, and don’t forget to flush a few times to remove the salts from your soil a couple of times in flowering if using the FF Trio.


I’m using 2 gallon fabric pots. Size of the plant compared to size of the pot I have to water everyday. Already the soil is hydro locked on one of my plants from trying to skimp from watering


Thanks @MidwestGuy, the soil feels dry maybe the slightest bit moist. When I let the plants go 2 days before watering the leaves are really dry and start to burn because of the light being so close otherwise I would let them dry out more. The leaves look thirsty ever morning too. I have the grow big nutes and the schedule shows 1:2 ratio of grow big/tiger bloom in week 9. Since I’m worried about nute burn I didn’t put in the grow big which is essentially the same thing just more nitrogen. I wasn’t sure how much nitrogen was to much or how it would affect the plant so I held off to see what she does before next watering

Thanks @OGIncognito, if she looks healthy should I just keep on with the watering schedule I have? Side note, the light recommendation says 18 inch above canopy during flowering for the sf2000 which is basically the same light set up I have and it’s at 11in right now. Also the reason why I’m not sure if she’s nute burn or light burn because all the tips of the leave are white(burnt) which could either be light burn or nute burn. Im worried if I let it dry out more the tips will get more burnt. Would you let the soil dry out regardless of light burn to prevent bud rot or keep them green without light burn watering everyday, but risk bud rot?


I forgot to mention lights are on 24/7, so drinks a lot of water. I often think of watering her 12 hours after a watering because the soil gets so dry but wait til the next morning. Is this enough for the wet/dry cycle?


The only issue I could see with your routine would be over watering as in frequency…not going to the dry cycle before watering or feeding again. The burnt leaf tips is just letting you know that she’s hit the nutrient threshold and I get this with every plant :love_you_gesture:


I would suggest 18/6 for the light cycle :love_you_gesture:


This makes you have to water more frequently

Happy cake day!

I would stop flushing and just increase the amount of drain you get when you irrigate to control the amount of salts in your soil.

Large EC fluctuations in the root zone are stressful, a good balanced watering program targeting specific drain % to raise or lower rootzone EC is ideal. Ideally, you will raise and lower your root zone EC slowly depending what stage of growth you are in.

I am not a soil grower, but from my experience irrigation events depend solely on achieving appropriate soil moisture and dry backs. So realistically in soil, some may need to water daily while others may need to water every 3-5 days.

Your plant looks hungry, which isn’t surprising as it looks like it has performed well for you!

I’m gonna point out thats ALOT OF LIGHT in a 24 hour period! Sf2000 11 inches away 24/7?
You mentioned white tips? That’s bleaching.

I have no doubt they’re using a crazy amount of water.