Hydroponics and PPM

U

UlyssesSG

New Member
Quick easy question for seasoned growers:

PPM. What should your ppms look like during bloom through to harvest.
Of course there are many factors with strain and other variables. I'm just looking to hear if there are any rule of thumbs for this.

I just changed my water and my ppm is 730. Before my change I was at 1300. They were happy as hell.
I usually add to the res every day until I get to about 1000 then I add ever few days until about 1200.

I go weeks without changing. Running 30gallon rdwc in a greenhouse. Everything is going good and I'm not looking for critiques but you can if you like, I'm looking to hear from fellow growers about their thoughts on ppm during the bloom through to harvest.

Thanks.
 
BobThe420Builder

BobThe420Builder

Well-Known Member
Ppm is very subjective

Water ppm?
Plus nutes....

I never go by ppm. Feed based in manufacturer suggested strength% and feed amount

Only reason I checked ppm in my DWC buckets is to determine if they are feeding and if I should increase, decrease, or keep the feed amount the same

Not changing a rezz for weeks is asking for trouble


Feed % changes from seedlings to harvest on pretty much every nite line, so a good feed schedule is your best friend
 
Billy the Mountain

Billy the Mountain

Well-Known Member
Consider using EC values since ppm is simply derived from EC but done with different scales. EC is universal, ppm depends on which conversion factor (.5 or .7) used. Your 1000ppm could be 40% different from my 1000ppm; EC is unambiguous.

Since the conversion factor of your meter is not stated, there's no way to know if your 1000ppm is 2.0 EC or 1.4 EC, a substantial difference.
 
F

FLLW

Member
If you’re using a feeding chart, just remember the entity that made the feeding chart makes their money off the nutes you use.

Especially early in the grow, I use 1/3 the suggested amount.
My results support this approach.
 
70's natureboy

70's natureboy

Well-Known Member
Southside112 said:
Never changed water 1 time. Just topped of my reservoir. Sothern Ag is your friend. I ran around 900ppm during flower. Stopped adding nutes last week and let my ppm drop to 300ppm by the time I chopped em. View attachment 4657120
Click to expand...
You must get a laugh out of all the threads about changing the res every week. If you know what you are doing you don't have to. I still change mine every 3-4 weeks anyway. looks good.
 
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