Nutrient vs size plant

I have some outdoor plants in 60 gallon fabric bags. I have been feeding with Fox Farm following their soil schedule. I only used about half the suggested amount at the beginning and as the plants grew I started raising to their suggested strength.

I am now at about 3-4 weeks into flowering, and last feeding followed their schedule again. The FF chart shows a suggested PPM range of 2380-2660 for this stage, and my TDS check showed at 2300 once I prepared my solution. But now I am reading on this site and others that rarely do people go over about 1400-1600ppm. My plants are big, given how they had about 15 weeks of vegetative growth. The are about 7-8’ tall now, and that was with topping and bending during the veg stage. I guess my question pertains to plant size vs the amount of nutrients fed. When I read recommendations for nutrient levels, I don’t see anyone asking the size of plants. Wouldn’t an 8’ plant need more nutrients than a 4’ plant? If yes, then do you raise the PPM or do you keep the PPM lower and just feed more often?

Thanks in advance for any replies.

Show us how your leaves look, if they re doing fine then why change things up. As long as you water to run off every feed to clear out salts then i personally think you can be a bit heavy handed with nutrients and come out well


Solid advice for sure! Following the flushing schedule will further safeguard you.

Alot of that is to help ensure healthy harvests for newbies, or autos and/or indoor plants. Outside is a whole different matter

Most indoors use 3-5-or 7gal bags. Hence the smaller feed.

1 Like

Bigger plants dont need a higher ppm… they need the correct ppm. Some plants are heavy feeders, others are not. If you are using FFarms soil chances are its already pre loaded with salts. The common treatment is to do a flush before the flowering feeding to remove some of the excess salts, but pre loaded soil cant be washed out. So your ppm will he really high because you are adding tona preloaded medium. If the plant is ok with it just keep on doing it. I would caution against any feeding in the last 2 weeks before harvest… it can make your bud harsh

1 Like

This has come up before and I just want to point it out here. FF uses 700PPM scale, no clue as to why since the is USA soil schedule where 500 is customarily used.
So week 9 700scale PPM of 2100 - 2380 translates to be 1500 - 1700 (5/7 X2100 = 1500)
Likewise 3.0 EC in 700 scale is 2100, while 3.0 EC in 500 scale is 1500

I take it you have your TDS / PPM set to proper scale?


60 gallon bags??? Jesus H Christ how big are they? :rofl:

1 Like

This is not my experience at all. Flush a fresh unused pot of FF soil and watch the tds drop with each gallon. Its good, especially with FF soil and nute combo, to flush after week 4, 7, and 10. FF nutes are designed to be watered to runoff each time you water and flushed out every few weeks to reset the ratios stored in soil.

1 Like

Yeah it works…sorta, not a big fan of pre loaded mediums because they tend to buffer poorly. Im mainly a organic based soil guy. I really never use commercial chemicals with the exception of extracts from sea plants. I have used salts in the past and found them to be too much work and quite expensive. If I grow indoors I prefer liquid hydro over FF medium. I will mix 50/50 promix hp with organic soil for seedlings etc under lighting indoors and not use salts.


Thanks for all the replies, I became busy and have not had a chance to reply. My leaves are good, no indication of nutrient burn. But I just want to be cautious at this stage and prevent burn. But I still want to give my girls all that they need. I am doing the recommended flushings according to schedule using the Sledgehammer liquid. I guess I was questioning having a PPM of 2300, when everything I read suggests that amount would be extremely high. The 700 scale used by FF now makes sense, I had no idea what the chart meant by that. I need to water them good tomorrow, and I guess I’ll stay with the FF suggested levels as long as all stays good. Thanks again.

I am all new to this. First time growing now that VA became legal. I read some of the advantages of using fabric bags and decided on that route. But the one thing that concerned me was how much quicker they can dry out. I leave town for a week or so a couple times during the summer, and figured I better use bigger pots so hopefully they don’t dry out. So yes, the plants are bigger than I thought they would get. This photo was taken just at the beginning of the stretch about 4 weeks ago, so they have grown even since then. :sunglasses:


They are damn beautiful brother well done!

1 Like

Monsters! Bigger the pot bigger the plant.

I dont see a little burn as a bad thing. When the tips get singed its a sign that you have fed them just over what they need, pushing them to grow more. Kinda like when you finish off the crumbs in the bottom of a bag of Doritos, after the last full chip, you could be done, but why toss away perfectly nummy chip chunks, you eat them…so will your plant.

Dont wash away nutes unless your plant tells you to. Water normaly and allow your plant time to consume what you have given. If she aint burnt dont put out the flame. You can always skip a feed and water twice in a row. Use your runoff and her reaction as a guide. If 2300 didnt mess her leaves up then she is comfortable with that amount, and you can carry on as you have been. Just track that ph so none of the nutes get locked out. If it drops bellow 6.5, water extra to bring it back up.

This and metric vs standard just urks me. Why on Gods green earth cant we just have a universal measure?!?! In my case, not using the whole lineup pays off. It doesnt matter what the chart says because im not trying to meet it. So I can track and use whatever ppm scale I want.

Your plants are just gorgeous :heart_eyes:. As a new grower, you have this well in hand. Excellent work.

1 Like