How Much Ppm Drop Is Ok?

[JMcG]

Hey farmers!
I have been wondering for awhile what everyone considers to be too much drop in your nutrient strength when checking ppm from day to day?
With UC and most hydro plants really will let you know when they have had enough to eat or when they want more pretty quickly. Visually there are markers to look for but keeping a log of ppm readings every day or so can really dial in what they want, higher readings than the day before equals over feeding and vice versa, we all know this... or should.
So my question is... How much drop are we happy with? Is it zero fluctuation that is the sweet spot as they consume equal parts of nutrients and water? Or is riding the fine line a road to gradual toxicity? I have read 10-15 parts drop as acceptable too, but that seems arbitrary depending on what phase of growth and how high your ppm might be at that stage.
Maybe 5-10% drop in concentration ? At 400 ppm that would mean 20-40 points of drop. Maybe too much?
I am interested in what you think!
Cheers!

 

[EventHorizan]

Hey farmers!
I have been wondering for awhile what everyone considers to be too much drop in your nutrient strength when checking ppm from day to day?
With UC and most hydro plants really will let you know when they have had enough to eat or when they want more pretty quickly. Visually there are markers to look for but keeping a log of ppm readings every day or so can really dial in what they want, higher readings than the day before equals over feeding and vice versa, we all know this... or should.
So my question is... How much drop are we happy with? Is it zero fluctuation that is the sweet spot as they consume equal parts of nutrients and water? Or is riding the fine line a road to gradual toxicity? I have read 10-15 parts drop as acceptable too, but that seems arbitrary depending on what phase of growth and how high your ppm might be at that stage.
Maybe 5-10% drop in concentration ? At 400 ppm that would mean 20-40 points of drop. Maybe too much?
I am interested in what you think!
Cheers!

Personally i think your over analyzing the situation. I have topped off nutes daily and i have let it go 2 days... The ec is less important to me that ph. I let my system drop from 1.5 to 1.2 all the time, and some times i run straight ro for 24 hrs and when i did that for the first time, i seen a really great lift from them. Brother your pretty intelligent and your doing exactly what you should by quoting these issues and gathering opinions.. If i was to say does it matter, probably a little, but not if its gonna drive you silly trying to find the g spot :)

What a lot of ppl i think over look about this stuff i think, is making it as simple for you as possible, because sooner or later, your gonna need simplicity, because of time restraints. Its the same as over packing a tent or room with plants and then needing to attend to the very back one and you have to pull them all out just to see if that one is hermed,,,,, when 30 mins later worth of dragging plants out of the way, to find out it was a shadow! :)

You could buy a lil feeder that will inject ml/hr/day into your solution, so with the info you are gathering you could use to set that up.. I beleive if you can get thier ec set perfectly and you maintain it, would be the best...

 

[HydroGuy]

I like to see my ec drop about 0.1 almost everday. Doesnt always happen but i feel like thats the sweet spot for me.

 

[JMcG]

Thanks for the input!
@ EH... what...?! Me over analyzing things? Ummmm.... yeah, that would be me....
I am just trying to nail down why I seem to end up with plants that just look a bit over fed by the end of a run, not badly but some burn and the " usual" canoeing of the leaves. I usually try to dial in the nutes ( probably too much) and keep them from dropping much if any over night. This usually means I am adjusting the epic and the rez every day or so. I really do want to set it and forget it but I kinda enjoy messing with it to see if I can get it dialed.
@ HG... that is good to hear. This week I set the epi and the rez at 410 ppm (500 scale) and 5.7 ph and didn't touch it all week, just logged its progress. It dropped about 25 parts for the first couple of nights and only about 15 for the last few. After seven days it dropped a total of 80 parts. Just a hint of tip yellowing but other than that the girls look awesome!

 

[fatawa]

Thats where i like my numbers..wen the tipity tip of fans r yellow..in not every strain will pray alnite so u shudnt adjust daily

 

[JMcG]

Cool. Thanks
I have been running the Flora Duo girls for almost three weeks or so now, they are now in week four of flower and seem really happy. For the last two Rez changes I kept the ppms at 410 and let them drop throughout the week to about 300. Ph was a bit low at first but raised slightly and stabilized within a day or two. Just a hint of tip burn and nothing too dark green!

 

[Highatollah]

Well my top off reservoir has about 20% higher nute levels than my system level but my EC stays stable. If I don't have my reservoir topping off then my EC drops about 0.1 per day.

 

[JMcG]

Thanks Aslan:)
Yeah , what I have seen over the last couple of Rez changes is :
A) my system with these ladies ( 24k , gg4, Death Star) in it only wants about 350 ppm, I tried 420 ish but now have some tip burn.
B) I backed it down to around 380 in the Rez and 360 in the epi and let it ride all week. Only dropped to 320 ish in six days. Ph started at 5.7 and swung through 6.2.

 

[RoeBuck]

I shoot for a 10-20 point ppm drop daily (500 scale) and a gentle rise on the pH. I set my top off the same or close to my system settings. I'm running a closed environment with co2 so my temps and humidity remain very consistent. Between 84 - 85 degrees and 60% rh till near the end, when I drop it to 45. Since temp and rh have a bearing on transpiration I think having them stable helps the plants to feed more consistently.