Hi all - this is my first grow, I’m getting getting ready to flip to flower. I’m using the FF trio of nutes and have 3 plants in 5 gal. smart pots going in a 2x4x8 tent. One is MK Ultra, GG,and then Blue Dream. The MK has been an easy keeper all the way, just drinks and grows. I started to flush yesterday to flip to 12/12 using Sledgehammer at ~6.4 ph. After 4 gallons the PPM is still 1100. The runoff started around 1,800. I put in 3, let it sit a bit, and then put in1 more while sucking runoff out with a turkey baster. I didn’t do the other plants yet (The GG runoff will be higher).
I’ve read three basic thoughts on this here and around the web; one is to flush about 1/2 gal. per gallon of pot size, second was to double the normal feeding, and last was to flush to about 300ppm. Normal feeding is about 1.5 - 2 gal. so I stopped to ask before drowning the poor thing or only flushing 1/2 way and not get rid of any salt buildup.
You all are always so helpful, thanks in advance for your wisdom, it’s much appreciated.
Since you are using FF nutrients, I would suggest that the flush you need is a Sledgehammer flush. Sledgehammer is a FF flushing agent, designed to flush the salt buildups caused by FF nutrients. I do a Sledgehammer flush at flip, and every 3 weeks after.
Here’s how FF says to use it:
Thank you for contacting FoxFarm, I’m happy to help!
To perform a flush with the Sledgehammer product, you will want to prepare the mixture at a rate of 2 tsp per gallon of water. You will use the Sledgehammer standalone. Pour the solution over the soil and use about twice as much solution to flush as you would if you were normally watering or feeding. For example, if on a normal watering you use a half gallon, for a flush you would use a whole gallon. Once this is done, let the soil dry completely. After that you can pick up with the next feeding as scheduled.
If you have any other questions please do not hesitate to contact us.
Keep flushing until you get the runoff PPM you desire. If I am flushing to remove salts, I run the PPM down to 300 or 400 and then give a light feeding. Then resume the normal feed schedule the next time the soil dries out.
Those were my numbers after running similar amount of sledgehammer flush before flipping. I got the amount of run-off recommended and stopped. Plants were starving a few days later as i didnt add anything at end of flush. Next time i’ll run at least a bit of cal-mag water at the end. From what i read the sledgehammer doesnt remove everything like flushing with an azzload of water potentially would (good and bad).
I have had good luck with high ppm doing a flood instead of a steady flush. What I mean is I would use a tub or garbage can and flood it almost up to the soil line. PH adjusted low ppm water. Smoke a bowl, then take a walk with the dog. Then pull it out of the flood bath and let it drain. 30-45 min. Never more than an hour. I never add an air stone but it would help flush. Osmosis seems to do it just fine for me. If you use a can or tub that would allow for the same amount of water as your pot size you are golden. Small garbage can on wheels works great for this. So does a kiddy pool or bathtub in a pinch. Especially for salts or an emergency shoot I accidentally over did it salt burn correction.
I’ve been reading about the FF nutes being a bit hot at full strength and I think I just found that out for myself. The other two ladies were close to or over 3,000ppm dry. Neither one had visible signs of burn though, were they just used to it? I have done a poor job of testing after feed, PPM was going way up in runoff and I didn’t catch it.
Anyway, I brought them all down w/ 5 gal of flush (5 gal-smart pots) and all had about 3 1/2 of runoff. I was reluctant to put FF nutes right back in since levels were so high so I gave 1gal w/cal-mag as suggested. That brought them all back up to about 550. I was planning on flipping the lights tomorrow and bring them up to about 1,000. Then go on as normal once they dry out. Does that sound about right to you all?
Thanks again and thanks in advance for the next round of questions too
I’m not sure I have any advice about runoff. I don’t measure it. I use the FF full schedule (except Rhize Up and Flower Kiss) at full strength throughout my grows, and If my plants show some distress, I do a soil slurry test. Otherwise, I just feed per the schedule.
