Trying to dial in nutrients

I've been going by this rule:
If ppm's are rising consistently then your plants are consuming more water than nutes and you need to dial them down.

I had 2 runs in dwc with same result. 2nd was a bit better but what looked like extreme nute burn was a bad phosphorus deficiency and probably more.
The thing is, my ph kept drifting a lot and also indicated that I was over feeding.
Using GH flora series at very low doses. My problem may be the tap water but it comes out at 82ppm using the .7 scale.

What is an acceptable daily rise of the ppm's? If it rose 30-50 a day would you think that's normal or over feeding? Is my tap water causing issues?
Water temps are always 70-72.

S13hitman said:

What is an acceptable daily rise of the ppm's?

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Minus 45 to minus 10. You won't get less bud going below that sweet spot, on the contrary. Less is more (to an extend of course).

In dwc i run my nutrients at a very low ppm say 300-600 as compared to upwards of 1200 in my aero and ebb n flow.

I've got 1 more run that's in stretch right now. Slight phosphorus deficiency and I can now see why the last 2 runs got so bad. But my ppm's were 440ish and then dropped to 250-300 when they started to look burned. All the mean while I was under feeding not burning them. But the whole time my ppm's never dropped by tthemselves over time. So that's my question, why do they keep rising.
PH is always 5.6-6.2 of course that includes me keeping it there with a lot of ph down.
Last run in dwc and already have a coco coir run in veg. Seems a little easier than dwc.

Your ppms should never rise, stability is key. You need to change the ratios of your nutrients if your having defs. DWC is for sure a low ppm system. But they are far less effected by swings, which would lead me to believe its an overfeeding.

If your burning the plants tone it down. Its been forever since i dwc'd but id start at like 200 ppm and then just gradually increase it till i hit around 1000. I think that in veg you can run pretty low, and in flower you need to be running higher during late stretch, and while the buds are forming and gaining girth, then you can drop it down the last two weeks since most of the hard work is done and your just finnishing....you should be fine. Oh ya, i was doing one plant per light with 600s to give you an idea of the size of plant and using the american vs the dutch scale.

Thanks All. Maybe I should try the lucas formula for the rest of this run...

Keep in mind the lower your nute strength, the more wonky your ph numbers will be and the harder it will be to keep them at a steady number. When your ph is off, your plant may take in water but lock out nutes creating ppm spikes in your reservoir. As mentioned above, the ppm should not rise unless there is a lockout. *Just as reference* I use drip buckets and run my ppm in veg at around 3-400. I gradually bump it up once I begin my P-K preflower feed. I fall at around 550-600 once I go into flower. By the peak of my flower feed I'm hanging around 850 ppm, but that is with 110ppm tap water/calmag/big grow and big bloom along with a bloom boost at the end right before I begin my straight water flush for harvest. I hope some portion of this was helpful.

S13hitman said:

I've been going by this rule:
If ppm's are rising consistently then your plants are consuming more water than nutes and you need to dial them down.

I had 2 runs in dwc with same result. 2nd was a bit better but what looked like extreme nute burn was a bad phosphorus deficiency and probably more.
The thing is, my ph kept drifting a lot and also indicated that I was over feeding.
Using GH flora series at very low doses. My problem may be the tap water but it comes out at 82ppm using the .7 scale.

What is an acceptable daily rise of the ppm's? If it rose 30-50 a day would you think that's normal or over feeding? Is my tap water causing issues?
Water temps are always 70-72.

Click to expand...

I'm using the feeding schedule on the right side by pH imbalance with the GH trio. Working great and plants growing fast. The only issue I have had is that my pH will drop about a .5 every 24 hours in a 15 gallon res, so I have only had to add pH up to my water/nute feed. I use RO water that comes out at 7 ph, and after adding nutes it's between 4.5 and 5 ph. Hope that helps somebody.

try switching to lucas and see how it works for you. what is your humidity at in your room. low humidity will cause plants to drink up water as opposed to eating up the nutrients. try to keep relative humidity above 55% google vpd(vapor pressure differential) it will show you a chart of where your relative humidity should be relative to temperature. good luck.