Daily acceptable PPM rise in DWC Buckets???

What is an acceptable ppm increase per day with DWC Buckets using GH nutes? I'm on the .5 conversion factor and let's say I start with a PPM of 850. The next day that goes up to 920. At that point I'll add back pure RO (Ph'd) and bring it back down, the next day it climbs again and so on. I've tried starting at 800ppm, 700ppm, etc, and it still goes up 50-70ppm per day.

I've searched and searched and couldn't find this problem discussed. I thought if you had PPM's right, that it would stay constant but I can't seem to find any answers online.

I used to fret over ppms until I discovered my new technique: never check. No more worries!

Unfortunately I really want an answer as I see my PPM's jump in veg (dwc buckets) about 50-70ppm per day and I'd like to see it stay steady. I couldn't find any answers online so I'm hoping someone here can lend some knowledge.

What are you using for a medium. Typically the only rise in ppm should come from water evaporation. Have you taken a TDS reading of your RO water? Ro water very seldom has a ppm below 5 to 10 and deoendind on the initail ppm and the type/quality of membrane in the filter you could have RO water with a ppm of at least 20 to 40 ppm.

Could this just be a simple matter of over feeding? This daily rise in PPM being nutrients not consumed by the plants?

redi jedi said:

Could this just be a simple matter of over feeding? This daily rise in PPM being nutrients not consumed by the plants?

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That's what I'm trying to figure out. Was at 820, it rose to 920, poured RO into a bucket until PPM was in the low 700 range. Same thing happened, went up 50-70 ppm in the next 24 hours. Took it to low 600's, same thing. Each time ph rises but not by heaps. If I set ph at 5.8, it's maybe 6 the next day.

5 gallon buckets, RO is 5-10ppm, using 6" netpots with hydroton. 1 air stone in each bucket fed by its' own pump.

greenstar said:

That's what I'm trying to figure out. Was at 820, it rose to 920, poured RO into a bucket until PPM was in the low 700 range. Same thing happened, went up 50-70 ppm in the next 24 hours. Took it to low 600's, same thing. Each time ph rises but not by heaps. If I set ph at 5.8, it's maybe 6 the next day.

5 gallon buckets, RO is 5-10ppm, using 6" netpots with hydroton. 1 air stone in each bucket fed by its' own pump.

Click to expand...

bring the ppm down again..


a rule of thumb is.. ppm's go up the plants are soaking up more water then nutes... ppm's go down then its opposite.. they are taking up more nutes then water over that time..

you need to find your sweet spot where it doesn't move much on you.. recently I had to find mine on my mother drip system and aero vegger... right around 1.20ms (EC) give or take.

ALSO each ppm meter is different... so your 600 could be someone elses 840.. and vice versa.. it gets worse as the number climbs since the conversion factors are 5, 6.5, and 7 for each different manufactured meter..

EC is the number everyone should use..
it's constant.. and those meters use it to convert to ppm



At 1500 the other meter reads 2100... feel me..

"everyone". hmmmm. To each his own I guess.

I grow dwc for a while now. Dont do daily ppm increase do it weekly.

Its very hard to tell yo exact number because genetics and enviornment play key roles.

Generally, I never need to go past 800ppm and thats when they are in the week b4 flushing. My vegging tree's[3ft tall by 5 ft wide] only can take 420-450ppm right now.

Also ppm rise is from over feeding or from micro-organisms. They are a no no in dwc as they cause big root probs. PH will go everywhere and ppm will rise. Gl homes

I grew 2 great Harvests in DWC with no PH / PPM meter. and got BOMB. you need meters when you lack a green thumb / use Iffy Materials (Tap Water)

ya its not eating what food it has is why its going up. if its happy the ppm will drop as is eats. ive also seen alot of those pens are reading TDS and not the ppm they say right on them. ive got meters here that read all forms and is what ive seen here by comparing them