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Proper PPM level

  • by Sabastian
  • Jan 01 2011 02:37 AM
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Posted 01 January 2011 - 02:37 AM

Greetings, first let me say I spent hours searching for this info on a variety of posts and never felt like I got what I needed. I am also posting to hydro because all the dirt people just confuse me. However, if the info I need exists somewhere here please either direct me or forgive me for asking again...

First time grower, hydroponic (stealth hydro system), using 2 sunlight 65 watt CFLs w/6800 lumens total, using Stealth hydro nutes. Temps in low 80's, humidity 40-50% usually, fan providing airflow. Ph in 6 gallon tank runs 5.9-6.2. Just got a TDS/ppm pen and tap water measures at 130 with 6.5ph. Plants are clones, indica (strain unknown to me), about 8 inches tall, and have suffered through too high a Ph about 2 weeks ago before I got my ph pen (previous pics on other posts).

I did a drain and fill w/o nutes 2 days ago because I think I have been burning my plants (had been using full strength, added over 2 days). Current PPM in tank is 298 (residual nutes?).

1) How long should I run this w/o nutes? Or should I go ahead and CAREFULLY add nutes now?
2) Assuming my tap water remains around 130 (is this ok or should I go get some RO water?), what PPM or nute level should I shoot for in tank?

I've seen posts on PPM in tap water not wanting to be over 100, other say less than 300 ok, so it is rather confusing.
I've also read posts where people are running 900-1200 ppm in their tanks, but that varies by strain and light source, correct? I have also read posts where people are at 300 ppm, though the best info I found said 600-750 ppm. I have also read that I subtract the starting water PPM from the total PPM to get the correct "nute" PPM... is this correct?

If someone can give me a nice, safe yet effective PPM level for nutes in tank given my tap water ppm that would be GREATLY appreciated. Believe me, I can't stand to see the girls suffer like this... it really bums me out.

Pics below show condition as of today. Most bad leaves were trimmed off, but a few visible, even in new growth. They are also droopy, but are actually perking up since yesterday. These plants are about 50-60 days post germination (I got them at 28 days) and I don't think they have grown as well as they should thanks to my nube screw ups.

Thanks guys and gals... you're the best.

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Posted 01 January 2011 - 03:35 AM

Greetings, first let me say I spent hours searching for this info on a variety of posts and never felt like I got what I needed. I am also posting to hydro because all the dirt people just confuse me. However, if the info I need exists somewhere here please either direct me or forgive me for asking again...

First time grower, hydroponic (stealth hydro system), using 2 sunlight 65 watt CFLs w/6800 lumens total, using Stealth hydro nutes. Temps in low 80's, humidity 40-50% usually, fan providing airflow. Ph in 6 gallon tank runs 5.9-6.2. Just got a TDS/ppm pen and tap water measures at 130 with 6.5ph. Plants are clones, indica (strain unknown to me), about 8 inches tall, and have suffered through too high a Ph about 2 weeks ago before I got my ph pen (previous pics on other posts).

I did a drain and fill w/o nutes 2 days ago because I think I have been burning my plants (had been using full strength, added over 2 days). Current PPM in tank is 298 (residual nutes?).

1) How long should I run this w/o nutes? Or should I go ahead and CAREFULLY add nutes now?
2) Assuming my tap water remains around 130 (is this ok or should I go get some RO water?), what PPM or nute level should I shoot for in tank?

I've seen posts on PPM in tap water not wanting to be over 100, other say less than 300 ok, so it is rather confusing.
I've also read posts where people are running 900-1200 ppm in their tanks, but that varies by strain and light source, correct? I have also read posts where people are at 300 ppm, though the best info I found said 600-750 ppm. I have also read that I subtract the starting water PPM from the total PPM to get the correct "nute" PPM... is this correct?

If someone can give me a nice, safe yet effective PPM level for nutes in tank given my tap water ppm that would be GREATLY appreciated. Believe me, I can't stand to see the girls suffer like this... it really bums me out.

Pics below show condition as of today. Most bad leaves were trimmed off, but a few visible, even in new growth. They are also droopy, but are actually perking up since yesterday. These plants are about 50-60 days post germination (I got them at 28 days) and I don't think they have grown as well as they should thanks to my nube screw ups.

Thanks guys and gals... you're the best.



130 for tap water isn't bad PPM wise. Mine is well over 250 ppm. The main issue with tap water is it's chlorine content which can be toxic to plants. If you use tap water I would let it sit out for at least a day to allow the chlorine to dissipate. Ideally in any hydro setup, the water quality is very important and you should really always use the best if possible.

Regardless of the beginning water PPM level. I would say you should include that with your final ppm calculation. For example if you are running 130 ppm and want to increase it to 530 ppm. Only add 400 ppm worth of nutrient.

I too have read where people recommend to "disregard the stock ppm" level and add the target ppm to the stock water ppm. Doesn't make sense to me. The plants can still absorb the original dissolved solids in the tap water :/

When it comes to hydro. Less is more nutrient wise. You'll run in to a lot more problems being on the high end of the spectrum than on the low. Just read the forums, there's 10x problems with nute burn than some minor deficiency.

By the size of those plants drop the ppm down a bit. Give em 300-400 ppm at ph 5.8-6 see how it goes. Should bounce right back and then you can add more nutrient.

Also, check your ppm daily. If the number rises and you don't have lots of water loss due to rez evaporation. Drop down the level and rise versa.

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Posted 01 January 2011 - 03:41 AM

To answer the question regarding high ppm levels. The ppm is determined by the size, age, and overall health of the plant. Over many weeks they get acclimated to nute levels and can safely handle higher and higher levels. And yes the strain is also a factor in ppm levels. Some seem to tolerate higher levels.

Just remember less is more. Plants take in nutrients in the solution at their own rate you can't force them to take in more.

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Posted 01 January 2011 - 04:14 AM

I suggest you dump the res, flush them and get all residual nutes out. Then give them fresh nutes at a mild level, PH 5.5 to 5.8 and see what happens. I let my PH float a little.

130 tap isnt a big deal IMO

Also I am on my 3rd location with tap water and dont let water sit out. Never had issues

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Posted 01 January 2011 - 04:32 AM

i would uses RO water and be feeding 800 to 1000 PPM at a 7 conversion tester on plants that size i don't see burn but N and cal/mag def

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Posted 01 January 2011 - 03:14 PM

I don't think you "need" RO water. But if you want a cheap investment that will pay for itself in healthier plants and slightly less res changes I say buy it. worse water was produced primo plants.

by the time the plant has its third set of leaves i'm at 1000 ppm. A week after that its up to 1400.

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Posted 01 January 2011 - 09:52 PM

Wow, thanks for all the info and suggestions. I kinda combined them, and after a flush decided to continue to use the tap water w/ aquarium chlorine remover, ph to 5.8, added nutes at half strength with total ppm at 588 (water started at 140), then wait a couple days to see if they improve. As Caesar5000 stated, it could be more of a deficiency problem. If they are not improving by day 4 and ppm is still near 500, I'll bump up the nutes into the 800-1000 range and monitor closely. Maybe my issue has been a combo of bad ph along with too weak a nutrient mix this whole time. Now that I have the ability to actually test how strong things are I will be much better off (hopefully!).

My hats off to those farmers who really get this down... growing is easier said than done! There is a lot to learn and I appreciate the assistance.

Thanks again!

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Posted 01 January 2011 - 10:53 PM

its probably better to just put a air stone in a five Gal. bucket then adding chlorine remover
even at 500 PPM your new growth will be fine but ones you see new growth bump it up

your dead leaves wont start looking better but new growth will come

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Posted 05 January 2011 - 05:26 AM

Thanks again for the info. It's been a couple days and I've been keepin track of ppm and ph closely. On 1/1/11 I followed advice, setting ph at 5.8 and ppm at 588 (water in tank started at 184, higher than how it tests from the tap, even testing every gallon). A couple hrs later it was ph 6.4 and 680ppm, ph downed then to 6.0. On 1/2/11 ph back up to 6.4, 710ppm, ph downed to 5.8. Today 1/4/11 ph is 6.0 with 780ppm. Plants appear better with new growth sprouting, but some "newer" growth still shows that dying back crap and some curl (don't think I'm just seeing previously damaged leaves). I also don't understand why the ppm would go up, other than they are drinking the water and increasing the concentration (?). So, a couple questions:

1) Should I increase nutes into the 1000 ppm range or wait a bit?
2) As Caesar5000 stated, maybe this is more deficiency than burn. With the new info, any opinions?
3) Does it damage/weaken/shock the plant to cut off bad leaves in the plants current condition?

I know these are nube questions that maybe should have been asked in the nube section, but I really want input from hydro growers. I GREATLY appreciate your help and I hope that someday I can return the favor to others, so thanks again.

(After I posted the pic, I compared it more closely to the ones from 1/1/11, and maybe I am just seeing the same damaged leaf, but I don't want to jump the gun... these poor plants have suffered enough!)

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Edited by Sabastian, 05 January 2011 - 05:31 AM.
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Posted 05 January 2011 - 05:56 AM

PH...PH...PH! They'll come around. Most defs are from high or low ph. with young plants.
5.8!:devious:

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Posted 05 January 2011 - 05:57 AM

Also, check your ppm daily. If the number rises and you don't have lots of water loss due to rez evaporation. Drop down the level and rise versa.


Was reviewing what you all said and noted this again... I think the tank is down about 1/2 gallon (it's marked as to where 6 gallons is).

I tried to take up close pics of the new growth but my camera sucks. However, the leaves on my plants have always appeared to be smaller than many of the other pics I've seen. Maybe the particular strain, or they are lacking what they need to grow?

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Posted 06 January 2011 - 03:18 AM

your PH is rising because the plant are eating the nuts bring the PPM up to at lest 800

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Posted 08 January 2011 - 06:17 PM

Thanks for the info. Plants are definitely recovering now with lots of new growth. I do see some of the new leaves showing just a bit of browning, nutes in the low 800s, so I think I will try a small push to 1000 and see how they do. Ph has been staying steady at 5.8-6. If they burn at least I will know what the ranges are... it's all a learning experience.

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Posted 08 January 2011 - 07:18 PM

while tap water ppm is a concern the bigger thing to consider with tap water # of 130 is what is the content of the water. Calcium and magnesium in the wrong proportions well wreck havoc. If you are happy with the recovery great, if not try using RO water.. You can get it at walmart from the culligan dispenser. RO water will be VERY close to 0 ppm

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Posted 08 January 2011 - 08:09 PM

i had not notice you using a airo-ponics if your roots are submerged in water then you should try to keep a PH of 5.5 5.8 should be your high point i would stay in the 800's for a week or more them bump it up if need be

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Posted 09 January 2011 - 03:31 PM

I can't figure out how everyone else is getting such high ppm levels so early. I never break 400 in veg or 600 in flower. Anytime I try to feed em more they raise the ppm 70-100 everyday and ph drops, which makes me think there not eating. I use a deep water culture system for reference.

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Posted 09 January 2011 - 04:01 PM

I can't figure out how everyone else is getting such high ppm levels so early. I never break 400 in veg or 600 in flower. Anytime I try to feed em more they raise the ppm 70-100 everyday and ph drops, which makes me think there not eating. I use a deep water culture system for reference.


it sounds like your using 5 conversation tester that would make your # make more seance

what are you using for light?

your right if your PH is going down and PPM going up the your nuts are to hot

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Posted 11 January 2011 - 07:05 AM

your right if your PH is going down and PPM going up the your nuts are to hot



Hmm, I'm gonna have to watch this as my ppm was going up just a bit before I added more nutes. I figured that was due to water use/loss. Plants look the best they have however, so I will just watch. I did ph it up just a tad yesterday as it was reading 5.4, increased it to 5.6 so no radical change there. Thanks again for all the info! Maybe I'll get some smoke out of these guys after all!

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Posted 11 January 2011 - 04:11 PM

it sounds like your using 5 conversation tester that would make your # make more seance

what are you using for light?

your right if your PH is going down and PPM going up the your nuts are to hot


No, I'm .7 conversion. I'm 400 mh veg and 600 hps flower. I swear it feels like I've had some kind of fungus or disease the whole time I've been growing.

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Posted 11 January 2011 - 04:31 PM

No, I'm .7 conversion. I'm 400 mh veg and 600 hps flower. I swear it feels like I've had some kind of fungus or disease the whole time I've been growing.


that is ode but if the plants are healthy your saving money on nut's at lest

do you clean with bleach in between runs?

whats the PPM of your tap water ?
do you have good air movement/exchange ?


Sabastian i would stick with PPM of about 800 till your plant fully recover and if they look good just run with it


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