It's going great, now is when I mess it up or not

So we have a GG Photo grow going and it’s been going great so far. We’re at the 2nd week of flower from flip and it looks great. For the last 4 weeks I’ve been following the FF trio schedule as written. Schedule says I can feed up to twice per week which for the last 4 is what I’ve been doing. They look great with no issue, but the schedule during most of flower is anywhere from 2300 to 2520 ppm. I note that most posts I’ve read and articles say around 1600 is plenty of ppm, so I’m wondering if 2300 + is far too much nutrient for GG photos. The plants look fine although most everywhere I’ve read these girls are moderate on nutes, and 2300 + isn’t moderate from what I’ve read.

So before I get into lockout or some other nutrient issue on these girls, should I just bring the ppm down to 1500 to 1600 from here on out?

Also have read 2 competing theories on what happens when. you use sledgehammer which is the second question I have. Some folks speak of disaster in mid grow using sledgehammer and others say it works just fine. One theory on the disaster side I read is that the soil may have been saturated with nutes and the sledgehammer opened the root throttle wide open and they overfed the plants. The other complaint on this was they stripped all nutes and the plant suffered.

So for the last month I’ve been doing full FF nutes twice a week on GG and so far it looks good.

Any advice on which tact to take? Either just bringing down the nutes to 1600 max or flushing and immediately fertilize after to 1600? Seems like we’ve. been overfeeding according to most info I’ve read, just because FF wants to sell more nutes doesn’t mean I have to follow the ppm and schedule they put out.

Just don’t wanna shock and harm these plants and also don’t wanna get into trouble from over feeding.

I’ll measure runoff today and post. Thanks to anyone who has some advice.

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should have mentioned, for this grow they’re all in fox farms soil.

Following as mine is 1800ppm 1st week of flower.

Fox Farm’s USA soil feed schedule is in 700 scale. No clue why they use that scale. I think 500 is much more common is USA. Anyway, when In used FF Trio I put this conversion schedule together. All of my TDS/ppm pens used 500 scale.

When you convert 700 scale 2300 ppm to 500 scale you are at 1600+_
If I went 100% per feed schedule, the next time I did water only or calmag only. You do need to watch for calcium deficiency with fox farm. I am surprised you have not encountered it.


You doing GG ILGM or another strain? Most I’ve ever seen anyone talking about a max, and a few generalized guides indicate 1500 or so ppm max throughout the grow. None of these are showing note burn at all.

I decided to just deep water till drain this week and going forward just one Fert a week at the 1500 ppm.

Still wondering if I should flush though. No sign of burn so I’m thinking I can just water down the ppm for now.

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Your runoff readings would tell you if you need to flush. Is your PH lower and PPM higher than when you started?

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I’ve used cal mag twice now. Not this time but last time I watered with RO I cal /mag’ed.

We use a bluelab combo for pH and TDS, the meter is set to 700 scale. So when people are referring to their ppm around here are they using the 500 or 700 scale?

What I’ve been doing up till now is fertilizing every 4 days, kinda twice a week.

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1600 ppm would be 500 scale
It is good your pen can switch between 500 700 EC. I now use a bluelab conductivity pen and I can do the same.

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Well it’s a bit difficult to check runoff. We use cloth pots sitting on 16" risers in 16" trays. Since the plants are well into the trellis now there’s no easy way to flush or pull clean runoff from the pots. There’s already fertilizer residue in the bottom of the trays so I can’t get an accurate reading.

I suppose I could try and weasel a tray out from under a pot so long as I’m not disturbing the plants too much.

Using their schedule it’s unclear whether they’re calling their ppm based off of the entire nutrient line shown on the schedule or what. Absent any specific directions I assume that top number is in the event you’re using the entire lineup of nutes which up until now I’ve only been using the trio.

And absent any other advice I’ll just ppm down to 1500 at the 700 scale using the rest of the line going forward.

pH of the water has always been between 6.3 and 6.5, again haven’t checked runoff yet.

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Im doing Blue Dream autos using fox farm trio. Ive noticed a little bit of nute burn at the tips but not enought to have me worried. The plants them selfs are thriving.
On a side note though im using pro mix hp not soil. I dont know if that matters but i thought i would mention it. I also feed every other day.

By any chance would you know if a vivosun TDS pen is 500 or 700 scale? Thats what im using at the moment.

I just found something interesting on another site. The information there mentioned that the soil schedule, and likely others, is showing how much of each fertilizer to put in WHEN USING THEIR ENTIRE LINE. That would mean that the ppm on the schedule is taking into account all the nutrient line nutrients, and it also mentions that the amounts shown on the schedule are assuming you’re using the entire line rather than just the trio.

For those using just the trio throughout their grow, are you adjusting the amounts by desired ppm or just using the amounts they say to use when using the entire line?

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Im just using their green feeding schedule at half dose with calmag added.

Been there. I used to use a 150ml syringe to suck up the runoff then wipe the saucer down as best I could. It got to be a pain in the A. So put the pots on racks and went with smaller heavier saucers

Slide the tray out, collect the runoff and wipe it off.

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It looks like a Wiztech multi pen we also use. Looks like an OEM pen that you can find under a bunch of different brand names.

The Wiztech is a 700 pen, assuming it’s the same one. I don’t think vivosun makes their own so a fair guess is it’s the same, so 700. Next time I fertilize I’ll use both and let you know.

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Thanks,I plan on getting a bluelab tds and ph but haven’t had the chance yet. Too busy trying to get a new light lol

We have the pots on risers so I can get a tube or something down in there to suck up the runoff I guess. I will need to remove and clean the saucer though, then put it back under and water till runoff.

We copied a lot from Mr. Canuck :slight_smile: . And on a side note about that channel, We went through multiple channels, forums and sights and finally settled on the equipment list for our setup. A few weeks later Canuck put out his latest video to YT and lo and behold the setup he used for his last post is exactly the same equipment, down to tent, light, fan, pots used etc. That was completely out of left field, but apparently he has new sponsors so the equipment changed again :slight_smile:

Bluelab is the way to go for hobbyists I think. Much more stable ph readings than using the pen. Very responsive and the TDS is fast as well, although I haven’t used it often. I’ll start now though.

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You can use a turkey blaster few bucks at the grocery store also good for watering seedlings