My Name is Mike
Well-Known Member
Thank you for explaining. Makes much more sense to me now. Appreciate the recommendations, I began reading a few already.I read over that report and there's a lot of info missing or that's not the whole report.
No mention of pH, ppm, calcium/magnesium, carbonates, alkalinity etc.
Nothing nasty in what is shown tho.
Your ppm from the added water will only be a percentage of the 130 depending on how much the whole system holds.
For example say the total is 10 gallons and you have to add one gallon to top up. You're only adding back 10% of the total so you'll raise the water ppm by 1/10th or 13ppm. Once you have had to add back 10 gallons then you will have added an extra 130ppm of water minerals and be up to 260. A bit less as the plants will have used up some of what was in the water but not much if you have better nutrients of the same minerals already there.
It's not that hard to keep track of that kind of stuff so you know very closely how much of the ppm is water minerals and how much is the nutrients your plants need to grow with.
I rarely change my nutes until after the stretch and have done many DWC grows without changing nutes even once. Been doing it since '01 so have had a bit of practice. It's crazy to toss out good nutes on a weekly schedule especially when plants are small and eating very little of it. Just makes the company richer when you have to buy more often.
We buy RO water for drinking and my plants as our water comes from a dugout on my property and gets filtered down to 5 micron but no sterilization. It's also around 400ppm and fairly hard at pH8. Next time I have a few hundred to spare I'm setting up my own RO unit.
I'm partial to Jorge Cervantes, (have two of his books), and he has a beginners book in there that goes a lot further than just the basics. Rosenthal is another golden oldie tho when I wrote his column in Cannabis Culture magazine back then about trying to make DWC work for pot he didn't think it would likely work well. Changed his tune since. I've always used RubberMaid tubs for my grows but using two of the new ones with cold weather plastic the roots wouldn't grow so after 3 weeks I pulled the survivors and put them in pots of soilless ProMix HP. I really think there is something in the new plastic that screwed with the roots but haven't been able to find any info after searching around for clues. 3 Critical Mass clones in one tub and 6 CBD plants of 3 strains in the other. Never had that happen after around 50 grows. Same nutes I've been using for a couple years now so it's got to be something else.
When I did a complete rez change out, I started with 480 ppm minus 80 PPM base water 50/50 distilled and tap PHed to 5.9. Over night at my morning reading today, it dropped to 360ppm and PH spiked to 6.7
I was concerned my PH meter was off so I ended up recalibrating it. This sudden drop in PPM and spike in PH, what would that tell you?
PH meter was fine.