Drinking only water

Tone5500

Well-Known Member
Ok 600watt grow in 5 gal dwc I'm in week 5 of flower I'm feeding 1100-1300 ppms , I'm feeding grow , micro, bloom , with koolbloom,flora nectar , with RO water and dyna-grow mag-pro. Up til like two weeks ago the girl was drinking about a gallon of the res. and the ppms would drop from 1100-1300 to around 850 or so so I would just top off with water and bring ppms back up but last week or so she is only drinkin water I will too off with the Ro water and the ppms won't change but maybe 50 or so , is this normal the deeper you get into flowering any help thanx , res temps get to about 73-74 in hottest part of day canopy temp gets to around 82 ground temp 74-76 and humidity under 30%
 

Bucees

Well-Known Member
If your res level lowers and the PPM stays the same that means she is eating nearly exactly what you are feeding her. This should always be your goal when dialing in plant specific nutrient levels. If she was just drinking water the PPM level would rise drastically.
 

WestDenverPioneer

Well-Known Member
Check your pH.
If the pH is not correct your plants cannot get the elements out of the solution. It doesn't matter if you're running 600ppm or 1200ppm if the pH is incorrect the nutrients will sit there and water will be the only thing taken up.

You can go ahead and add a week of flowering to your schedule. Do this any time your plant sits idle without taking up nutrients.

Once you adjust the pH the plant will resume its growth. Just keep on, keeping on, and let it finish (why I said to add a week).
 

Tone5500

Well-Known Member
If your res level lowers and the PPM stays the same that means she is eating nearly exactly what you are feeding her. This should always be your goal when dialing in plant specific nutrient levels. If she was just drinking water the PPM level would rise drastically.
Yea that is how it has been for basically the entire grow , up untill last week or so I can add back a hole gallon of 20 ppm of ro water and my ppms have will only drop 50 or so ,my ph stays where I adjust it always never really gave to I just bumped it up to 6.2 to see if that help but before would keep it at 5.8
 

skunkd0c

Well-Known Member
yes its normal, imo, the growth patterns and feeding patterns are not linear much of the growing
comes in growth spurts
i find myself adding food twice in a week and at other times may leave it 2 weeks with no food
 

churchhaze

Well-Known Member
Yes, sorry I deleted my message. I read the original post a bit backwards. It's still normal though. After the stretch, nutrient and water requirements both taper off sharply.

The fact that your ppm was going down before implies that you didn't have it too high like some others are suggesting. It may have been able to utilize an even higher ppm.

For your setup and strain, I'd keep using 1300ppm during the stretch period, and lower it to 800 or so after week 5.
 

WestDenverPioneer

Well-Known Member
Keeping the pH exactly at one value has never given me the best results. At least one deficiency would always show up by the end.
I used to try to keep it like that but it turned out that a small shift within the safe range of pH allows the greatest uptake.
Having a lower ppm may make things easier for you. I find the small shift in pH that I'm looking for occurs in lower ppm solutions. High ppm solutions tend (for me) to have larger pH changes and more problems overall.
 

Tone5500

Well-Known Member
Ok so a little update went to fill my res. for the day and last night ppms were set to 1300 and today a gallon of water gone and ppms at 1650 , so I'm just going to add back water untill ppms are down to 600 then bring them up to 800-1000 ,
 

churchhaze

Well-Known Member
I'm just curious, does your meter use 0.50 or 0.70 to calculate ppm? I have a feeling I'm used to 0.70 while you're used to 0.50

I never go above 650-700 in dwc and 1000 in aero, and with many many strains. Its just not needed when the roots have such ready access to nutes.
 

Alaric

Well-Known Member
IMO, it's about nute control-------the larger the rez------the less attention required. Presently, my rule of thumb, is at least 25 gallons per 1K of flower lighting-----also, I like to let my ph swing from 6.0 to 5.3----just look at the nute absorption charts/ph levels.

Just my ramblings,

A~~~
 

waterdawg

Well-Known Member
"I'm just curious, does your meter use 0.50 or 0.70 to calculate ppm? I have a feeling I'm used to 0.70 while you're used to 0.50"

Why would that matter? I always thought ppm's were ppm's and the ec reading would be different depending on multiplier. Maybe thats why I'm so amazed when I see people running such high numbers. If I ran more than 750 ppm's my plants would jump out of pots and run away lol.
 

churchhaze

Well-Known Member
It's the other way around. TDS meters are just EC meters that approximate ppm based on conductance. It is only an approximation

0.5 one that seems more accurate for hydro nutes. The total nutrient ppm for my mix #15 is 642ppm as calculated in hydrobuddy, and the estimated EC is 1.3mS/cm. That almost perfectly lines up with the 0.5 ppm chart. To avoid confusion, I'm just going to convert my ppms to EC in the future and list those.

Actual ppm can be calculated as mg/L, so if you put 50mg of nitrogens worth of a salt in a liter bottle and fill the rest with water, that solution has 50ppm of N. That's a lot different than the approximation the TDS meter gives based on EC.

Had I known this when I got my tds meter, I would have got an EC meter instead to avoid the confusion.



I always thought ppm's were ppm's and the ec reading would be different depending on multiplier. Maybe thats why I'm so amazed when I see people running such high numbers. If I ran more than 750 ppm's my plants would jump out of pots and run away lol.
 
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churchhaze

Well-Known Member
1300ppm is pretty damn high on the 0.50 conversion scale. It's 2.6 EC which is very high. On the 0.7 scale, that's 1820ppm (according to the chart I posted last post)

I'm going to have to take back what I said previously. 1300ppm is way too high if your meter works on 0.50.

1300ppm on a 0.70 conversion is around 1.9mS/cm

mine is .50
 

Tone5500

Well-Known Member
Ok so I have just been adding back 20 ppm of ro water for the last 5 days now and the ppms have only dropped 150 ppms scents then , and now my plant is starting to show signs if potassium def. , what should I do dump res. and refill with lower ppms , ? And a ph of 6.5???
 
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