Need some extra eyes and advice

My Name is Mike

Well-Known Member
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.

:peace:
Thank you for explaining. Makes much more sense to me now. Appreciate the recommendations, I began reading a few already.

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.
 

OldMedUser

Well-Known Member
It's normal for the ppm to drop as the plants feed off it and the pH to go up but that's a bit too much. I suspect your water.

I saved a post I made to someone else so will save me time.

When you are preparing to water/feed your plants you test the pH. If anything it's likely to be too high. If the source water is below 7 they treat it with something like calcium carbonate to get it above 7 as acidic water corrodes the pipes and wipes out the bio-film that lines pipes. Remember Flint, MI?

Check your water out of the tap. It should sit in an open pail for a day to let the chlorine evaporate out of it or if using water jugs get a small aquarium air pump and stone to aerate the water and dissipate the chlorine faster. If your supplier uses chloramine then you're stuck with that unless you run it through an RO filter first. Supposedly ascorbic acid, Vit. C, gets rid of it but I don't know if that's true or how much to use. Good for the plants anyhow so won't hurt.

Check the ppm as well. Ours is around 400ppm and I won't use it on my plants. pH 8 too. High ppm tap water is going to be alkaline and may need some testing to figure out how much pH down you need to get it stable around 6.5 for soil plants. 6 - 6.5 is good for dirt farming and 5.5 - 6 for hydro.

Take a known amount of water, quart/liter/gallon, and test the pH. If needed carefully add a few drops at a time mix and wait 15 min to test again. Keep track of how much pH down you use so a syringe would be good. Suck up 20 mls and use that so you see how much total to get it at 6.5. Once there let sit overnight and test again. If its gone up knock it back down to 6.5 and let sit 12 hours then test again. Stir it good or run an airstone in it to make sure it's well mixed.

PITA I know but you only have to go thru it once. Once it stays at 6.5 then you add up how much pH down it takes to make it stay there and you know how much to add to that volume of water to get it right. Carbonates are slow to react so if your water has lots it takes a while for the acid to neutralize it all.

pH can change with the seasons so check the tap water every so often. Don't have to do the whole procedure again.

If you are adding nutes to the water put in everything you're going to add first then test pH and adjust. Sometime the nutes will bring down the pH a lot depending on the mineral content of your water.

With RO water and pH Perfect nutes I just add my nutes to the water and give it to my plants. :)
 

My Name is Mike

Well-Known Member
It's normal for the ppm to drop as the plants feed off it and the pH to go up but that's a bit too much. I suspect your water.

I saved a post I made to someone else so will save me time.

When you are preparing to water/feed your plants you test the pH. If anything it's likely to be too high. If the source water is below 7 they treat it with something like calcium carbonate to get it above 7 as acidic water corrodes the pipes and wipes out the bio-film that lines pipes. Remember Flint, MI?

Check your water out of the tap. It should sit in an open pail for a day to let the chlorine evaporate out of it or if using water jugs get a small aquarium air pump and stone to aerate the water and dissipate the chlorine faster. If your supplier uses chloramine then you're stuck with that unless you run it through an RO filter first. Supposedly ascorbic acid, Vit. C, gets rid of it but I don't know if that's true or how much to use. Good for the plants anyhow so won't hurt.

Check the ppm as well. Ours is around 400ppm and I won't use it on my plants. pH 8 too. High ppm tap water is going to be alkaline and may need some testing to figure out how much pH down you need to get it stable around 6.5 for soil plants. 6 - 6.5 is good for dirt farming and 5.5 - 6 for hydro.

Take a known amount of water, quart/liter/gallon, and test the pH. If needed carefully add a few drops at a time mix and wait 15 min to test again. Keep track of how much pH down you use so a syringe would be good. Suck up 20 mls and use that so you see how much total to get it at 6.5. Once there let sit overnight and test again. If its gone up knock it back down to 6.5 and let sit 12 hours then test again. Stir it good or run an airstone in it to make sure it's well mixed.

PITA I know but you only have to go thru it once. Once it stays at 6.5 then you add up how much pH down it takes to make it stay there and you know how much to add to that volume of water to get it right. Carbonates are slow to react so if your water has lots it takes a while for the acid to neutralize it all.

pH can change with the seasons so check the tap water every so often. Don't have to do the whole procedure again.

If you are adding nutes to the water put in everything you're going to add first then test pH and adjust. Sometime the nutes will bring down the pH a lot depending on the mineral content of your water.

With RO water and pH Perfect nutes I just add my nutes to the water and give it to my plants. :)
Another great write up. Thank you! Just made me think of a few steps I wasn't doing correctly that definitely would and I'm sure did impact my rez negatively.

I do let my tap water sit in 1 gallon jugs, typically a minimum of 48 hours uncapped. After 48, I put 1 in my mini fridge to keep cool and that's what I use to top off rez with a constant rotation. After I test my rez PPM & PH, I adjust the cooled jug to the 5.8 PH range and use immediately. I'm not giving it time to mix or settle beforehand in case it has fluctuations which would definitely explain the spikes.

I tested my tap water just now to run this trial and it came in at 148PPM, 8.3PH.

6 drops of PH down took it down to 5.56

30 mins later, no change. I'm going to test again in the morning to check for changes.
 

My Name is Mike

Well-Known Member
I only see this on 1 or 2 other leaves, this one is the whole set of leaves. The tips of all the edges look burnt. It was suggested it was burnt from my LED but it's only this and a few others which doesn't lead me to believe it's from my LED. I may have answered my own question that it could be nute burn but only this set of 5? PH has been 6.1, 340PPM. Just strange shit. It's exposed at the top of canopy, nothing underneath has this.
 

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OldMedUser

Well-Known Member
Could be that one was in the heat a bit more and was drawing more water with nutes to cool itself and got a touch of nute burn.

Do you have good airflow across the canopy? Helps a lot.

I wouldn't worry. If it was real nute burn all the big leaves would be getting it.
 

Whatever98

Member
I had the same exact happen to me a couple months ago... Twice. One was from too muvh epsom salts. And the other was a single fungus knat that took me hours to find. I found him right after soaking the soil with water. The fucker came up right out of the soil.
 

My Name is Mike

Well-Known Member
Could be that one was in the heat a bit more and was drawing more water with nutes to cool itself and got a touch of nute burn.

Do you have good airflow across the canopy? Helps a lot.

I wouldn't worry. If it was real nute burn all the big leaves would be getting it.
Airflow is good. I'll post a week old pic to show since it's nights out right now. I made a few changes recently. I have this black fan hanging to put good airflow over canopy. The smaller white fan that used to be up top is now below the canopy. I also increased the ventilation fan using my variac and dimmed my lights just a smidge, 90% output. I realize 200watt cob led in a 2x2 could be too much so I'm trying to keep the foot off the gas so to speak. I've since taken off the lamp shades to keep a good spread of light and less hot spot potential. When I flipped, I did around 21 hours darkness to change the light cycle to kick on at night vs day. This made a huge difference keeping cooler cab temps.

Thanks for your knowledge.
 

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My Name is Mike

Well-Known Member
I had the same exact happen to me a couple months ago... Twice. One was from too muvh epsom salts. And the other was a single fungus knat that took me hours to find. I found him right after soaking the soil with water. The fucker came up right out of the soil.
This actually made me laugh because I spread some diatomaceous earth around my passive intakes about a week ago as a precaution. When I did my complete rez change few days ago, I pulled both WF out to sanitize the inside walls and found a dead, what I believed to be fungus gnat on the bottom floor of the cab. Forced me to do another thorough inspection on the plants and haven't found anything since. I used more diatomaceous earth under my cab to keep any critters away. I have carbon filter sheets that are clamped onto both intakes vents and the ventilation to avoid any easy access. Funny shit though, Thanks for sharing as I didn't think twice about finding that.
 
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