PPM rises past desired level

[aeviaanah]

Growing a deep purple in a 5 gal dwc....there is about 2 gallons of nutrient water mixed to 800 ppm. After a week or so i get ready to change nutrient solution and ppm has raised to around 1600 or so. Curious as to what may be causing this? Phd water in at 5.5 comes out around 5.3. Plant seems to be absorbing nutrients and is growing quit fast. I have around 8 large airstones pumping air into reservoir. Im adding supernatural brand grow 20-20-20...to around 600 ppm...a few additives like seaweed extract, root zone conditioner, and silica from dutch masters. Plant could use more light...only using two low watt cfl bulbs, just to get by till i set up 400 mh.

leaves are tending to look abnormally pointy and long...and are slightly disfigured when small. nice dark green, no purple hue, burnt tips or leaf curl. something is off as i have grown this strain in soil. plant has nice healthy rootball no slime or blackening of any sort.

resevoir water is ambient with room temperature...70-75 deg.

could be dealing with too much nutrients per the amount of light she is receiving?

why are ppm drifting up and ph drifting down, shouldnt it be opposite? i just phd water in at 5.7, this way if ph drop becomes a trend it will drop to around 5.5.

 

[reggaerican]

i been using supernatural for years and i love it.. first it sounds like your adding to much nutes! if your growing under flos then i would lower to around 500ppm and "not ever" go above 700ppm with those nutes. only ph your water once @ every water change thanks to the buffers. and third how many plants do you have? as far as the airstones go you only need one per bucket.. i kinda scratched my head at that one but to many airstones could also be a problem..

 

[aeviaanah]

too much oxygen?! how?

 

[Gixxerboy]

Your PPM is rising because the water is evaporating,when your water level drops your nutes become more concentrated upping the PPM which in turn causes the ph to drop.To keep this from happening add water back everyday.I'm running a 5gal res and a 10gal res. I add a half gallon of water a day back to the 5 and 1gal a day back to the 10.Mid week i pull if needed and ad nutes to bring back to the original PPM.As far a air goes the general rule is 1watt per gallon.I have been playing with different pumps and have been pushing the limit as far as i can and now running a 60watt pump with 6 stones.Two for the 5gal and 4 for the 10gal.Looks like the ocean waving around, best root systems I have ever had.Let Ur ph fluxuate between 5.2 and 6.5.Here is a chart from our site on ph ranges.

 

[snocat]

I have found that when your ppm rises that high above what you started at its because the plant is useing more water than nutes,and your ppm was to high to start with,also 75 deg. nute solution is a bit warm,my last grow was in 5 gal. buckets and towards the end they were useing a gallon a day,and temps were running high.it was a pain in the ass tending to the buckets.this grow I made my own rdwc set up so that is easyer to add water maintain temps and make flushing and res changes quicker.5 gal. buckets work good but they can be difficult to maintain temps when the plants start useing alot of water,less water higher temps,also you will need a shit load more cfls if you want to get a worth while harvest.also I dont think you can have to much air,unless its breaking roots,my water looks like its boiling. good luck

 

[Flo Grow]

And 5.2 ph is a major no-no !
MINIMUM 5.5 AND MAXIMUM 6.5 FOR PH !
Try to keep it 5.7 - 6.0, with 5.8 and 5.9 being the best for max nute uptake.
Read the chart above carefully.

 

[Gixxerboy]

And 5.2 ph is a major no-no !
MINIMUM 5.5 AND MAXIMUM 6.5 FOR PH !
Try to keep it 5.7 - 6.0, with 5.8 and 5.9 being the best for max nute uptake.
Read the chart above carefully.

Do you really think that their is much difference between 5.2 and 5.5?Now im not talking for an extended period of time or anything.Ph fluctuation is needed to insure you are getting a proper range of nutrients.Lets also not forget that all plants are not the same some like different PHs.At 5.7 to 6.0 your plants will never see any MN not that its need as much as the others,but see what i mean.At 5.2 your plants see K, CA, MN, B.I like to start off at above 6. and let her drop to 5.2ish and then bring it back up to 6.

 

[aeviaanah]

Your PPM is rising because the water is evaporating,when your water level drops your nutes become more concentrated upping the PPM which in turn causes the ph to drop.To keep this from happening add water back everyday.I'm running a 5gal res and a 10gal res. I add a half gallon of water a day back to the 5 and 1gal a day back to the 10.Mid week i pull if needed and ad nutes to bring back to the original PPM.As far a air goes the general rule is 1watt per gallon.I have been playing with different pumps and have been pushing the limit as far as i can and now running a 60watt pump with 6 stones.Two for the 5gal and 4 for the 10gal.Looks like the ocean waving around, best root systems I have ever had.Let Ur ph fluxuate between 5.2 and 6.5.Here is a chart from our site on ph ranges.

Great info! Thanks for posting my friend. So it is possible to have too much oxygen pushing to reservoir? What should i look for if the airpumps are causing the problem? In a 5 gallon dwc with a large plant i shouldnt have 5 gallons of water correct? I am keeping it around 2-2.5gal, this way roots suspend in the air and catch moisture from bubbles as they pop. Am i doing this right?

I have found that when your ppm rises that high above what you started at its because the plant is useing more water than nutes,and your ppm was to high to start with,also 75 deg. nute solution is a bit warm,my last grow was in 5 gal. buckets and towards the end they were useing a gallon a day,and temps were running high.it was a pain in the ass tending to the buckets.this grow I made my own rdwc set up so that is easyer to add water maintain temps and make flushing and res changes quicker.5 gal. buckets work good but they can be difficult to maintain temps when the plants start useing alot of water,less water higher temps,also you will need a shit load more cfls if you want to get a worth while harvest.also I dont think you can have to much air,unless its breaking roots,my water looks like its boiling. good luck

Thanks for the great post. I just have the plant under cfls because flower room is using 2-400watt hps. I do have a 400 MH, just waiting to set it up. Still thinking about what i want to accomplish with this next go around. Thanks for the good points! How much water did you run in the 5 gal buckets? I am around 2gallons, does this sound right?

And 5.2 ph is a major no-no !
MINIMUM 5.5 AND MAXIMUM 6.5 FOR PH !
Try to keep it 5.7 - 6.0, with 5.8 and 5.9 being the best for max nute uptake.
Read the chart above carefully.

Thanks!

 

[aeviaanah]

deep purple

come check out the grow in sig guys!

 

[onthedl0008]

As said PPM will rise when the water evaporates as ur nutrients parts per million count obviously becomes more as ur water evaporates. Try to keep ur water level a couple inches below the bottom of the net pot at all times.
Keeping ur PH steady at 5.8 is also a nice spot to keep ur PH to allow for the PH swings that happen naturally in DWC.
With that being said.
If u keep ur water levels and PH maintained as closely as u can useing these rules.
PH will Rise if ur not feeding enuff.
And PH will drop if ur feeding to much.
UR PH WILL BALANCE NATURALLY ACCORDING TO WHAT UR STRAIN NEEDS.
Ur plants will tell u what they need.
Some strains SATIVA DOM will usually eat less and they tend to balance between 5.8-6.0 when u have ur feed schedule down proper.
INDICA DOM strains like to eat more and when feed properly will balance closer to 5.6-5.8.
U can keep it all together real nice by following these general rules of Green Thumb very simple as long as u keep these 2 rules proper.
Your water levels stable and ur PH proper.
Hope this all made sence and helps out.

 

[aeviaanah]

As said PPM will rise when the water evaporates as ur nutrients parts per million count obviously becomes more as ur water evaporates. Try to keep ur water level a couple inches below the bottom of the net pot at all times.
Keeping ur PH steady at 5.8 is also a nice spot to keep ur PH to allow for the PH swings that happen naturally in DWC.
With that being said.
If u keep ur water levels and PH maintained as closely as u can useing these rules.
PH will Rise if ur not feeding enuff.
And PH will drop if ur feeding to much.
UR PH WILL BALANCE NATURALLY ACCORDING TO WHAT UR STRAIN NEEDS.
Ur plants will tell u what they need.
Some strains SATIVA DOM will usually eat less and they tend to balance between 5.8-6.0 when u have ur feed schedule down proper.
INDICA DOM strains like to eat more and when feed properly will balance closer to 5.6-5.8.
U can keep it all together real nice by following these general rules of Green Thumb very simple as long as u keep these 2 rules proper.
Your water levels stable and ur PH proper.
Hope this all made sence and helps out.

Thanks for the great post, i will go check ph and ppm will get back to everyone with results. Ive always though you want water level real low? This way as bubbles pop they sort of mist the root zone. You are saying to run it way up high? 3.5-4 gallons? Submerging roots fully?

 

[dudeoflife]

Thanks for the great post, i will go check ph and ppm will get back to everyone with results. Ive always though you want water level real low? This way as bubbles pop they sort of mist the root zone. You are saying to run it way up high? 3.5-4 gallons? Submerging roots fully?

I'm not speaking for the fella who made that great post, but yeah-- you want to keep your h20 level the same throughout the week, about and inch under your net pot, if you want to keep your ph and ppm steady.

I would like to add that you want to keep your ph between 5.5 & 5.9 in DWC, because K locks out when it rises above 6.0. Your plant uses more K than any other element besides N over the course of the grow, and you shouldn't deprive your plant of this vital element.

Strangely, however, K becomes available again, optimally, after 6.8 in hydro. (that chart shows a huge range-- we're talking optimum absorption here ) Wierd! So that will account for the people who say "keep it at 6.5", etc. Because once it naturally rises to the magic 6.8 mark, K is flowing full force, and you see no noticeable loss in performance. That can probably account for the two schools of thought on PH in DWC. But you want it to be between 5.5-5.9 for optimum uptake for all elements, trace metals included.

 

[onthedl0008]

What ive always tried to do is keep my bottom 2 thirds of my root mass covered at all times.
The pros say the top third of the plants root mass like more air and the bubbles in our system spray enuff solution up into our hydroton as well as keep enuff humidity under the lid to give the exposed roots plenty enuff food.
U can grow a plant AERO. Looks to me like the NFT set-ups do better tho.
In DWC u can mimmick these styles just following the rules i guess.
But ive always liked the fact my plants roots where always fully submerged n able to get what they want when they want it however they want it i guess.
Ur plants can and will drink up to 3 gallons per/day in agressive flowering.
Keeping up with that will be close enuff in a 5 gallon bucket.
Play with it.

 

[aeviaanah]

I'm not speaking for the fella who made that great post, but yeah-- you want to keep your h20 level the same throughout the week, about and inch under your net pot, if you want to keep your ph and ppm steady.

I would like to add that you want to keep your ph between 5.5 & 5.9 in DWC, because K locks out when it rises above 6.0. Your plant uses more K than any other element besides N over the course of the grow, and you shouldn't deprive your plant of this vital element.

Strangely, however, K becomes available again after 6.8. Wierd! So that will account for the people who say "keep it at 6.5", etc. Because once it rises to the magic 6.8 mark, K is available, and you see no noticeable damage to your plants' foliage. That can probably account for the two schools of thought on PH in DWC. But you want it to be between 5.5-5.9 for optimum uptake for all elements, trace metals included.

Thankyou- what is a good ppm for an established and fast growing plant in mid-late veg? I will raise water to just below net pot.

Just check ph and ppm- Ph raised rather quickly in 18 hours..went up to 6.3...i will slowly bring it down to 5.5 again. Vast ph changes should be done slowly right? Is it ok to change reservoir water and have ph go from 6.5 to 5.5 in a matter of seconds?

Here are a few images, I am trying to figure out what is wrong with the plant. Startin to think it may be ph and/or over nutrient issues.

Upper fan leaves...lower leaves have a less distorted shape

upper leaf

uppermost...i accidentaly broke stem

 

[dudeoflife]

What ive always tried to do is keep my bottom 2 thirds of my root mass covered at all times.
The pros say the top third of the plants root mass like more air and the bubbles in our system spray enuff solution up into our hydroton as well as keep enuff humidity under the lid to give the exposed roots plenty enuff food.
U can grow a plant AERO. Looks to me like the NFT set-ups do better tho.
In DWC u can mimmick these styles just following the rules i guess.
But ive always liked the fact my plants roots where always fully submerged n able to get what they want when they want it however they want it i guess.
Ur plants can and will drink up to 3 gallons per/day in agressive flowering.
Keeping up with that will be close enuff in a 5 gallon bucket.
Play with it.

Absolutely! I know I'm a day late and a dollar short, but

I have seen the best gains after letting my plants to their thang, and coming back to a whole bunch of buckets with less than a gallon of water left.... Never measured the ph or ppm, the plants looked too damn good to really care.

Really though, your ppm are skyrocketing, but your plants look great. And you are worried. What gives?

 

[dudeoflife]

Uh huh. I see the pics. What's the matter? Looks great to me. Do I need a new glasses?

 

[aeviaanah]

What ive always tried to do is keep my bottom 2 thirds of my root mass covered at all times.
The pros say the top third of the plants root mass like more air and the bubbles in our system spray enuff solution up into our hydroton as well as keep enuff humidity under the lid to give the exposed roots plenty enuff food.
U can grow a plant AERO. Looks to me like the NFT set-ups do better tho.
In DWC u can mimmick these styles just following the rules i guess.
But ive always liked the fact my plants roots where always fully submerged n able to get what they want when they want it however they want it i guess.
Ur plants can and will drink up to 3 gallons per/day in agressive flowering.
Keeping up with that will be close enuff in a 5 gallon bucket.
Play with it.

Thank-you, this rule sounds good. I will raise water level. Plant is not drinking much yet, probably due to low lighting.

Uh huh. I see the pics. What's the matter? Looks great to me. Do I need a new glasses?

You dont see the disfigured leaves? They are also pointy. I have grown soil for years and have never seen this.

 

[dudeoflife]

OK- as far as the PPM in DWC, your plant has a huge tolerance to swings in the ppm. 600-2200. Some say 3000. How's that for a range? lol.

You start with 800, but then it doubles to 1600 after your plant sucks up more water. You speak as though it's a problem, when it is evident in the pictures that it isn't.

A MJ plant has a tolerance level of 400 ppm N, 400 ppm P, and 700 ppm K , 300 ppm Ca in hydro. So if the ppm swings to the point that you get a disproportionately higher amount of Ca to K over the week, for example, you will see some damage and yellowing in the leaf margins.

If your ppm rises and the elements maintain favorable proportions, Ca being the primary concern, you have no worries!

SO if it ain't broke, don't fix it!

 

[aeviaanah]

Yes but the leaf formation is not normal. What explains this?

 

[dudeoflife]

Thank-you, this rule sounds good. I will raise water level. Plant is not drinking much yet, probably due to low lighting.

You dont see the disfigured leaves? They are also pointy. I have grown soil for years and have never seen this.

Ok ok- the curling. Have you grown this same strain in soil?

Curling happens from time to time in DWC. It's not a death curl. It's probably a response to the ph being 6.3, as K is not being absorbed optimally. It's still being absorbed, though.

I wonder who told you that you have to have to make subtle changes to the ph over time to correct it.

That's not why I elected to make DWC my choice hydro method for my grows. I chose DWC because you can make substantial changes by simply replacing the medium, the water with a fresh mix, and see the improvements, sometimes, within hours.

Whoever started the rumor years and years ago that you have to make subtle changes to DWC ph probably mixed a batch of nutes that was either way too high to way too low in the PH, wrong to begin with, and was drastically different than the ph of the mix he was replacing. So, he tells everyone to make subtle changes, slowly, until you reach your desired ph.

Well, if you do that, you stroll through the optimum PH ranges of a lot of elements, and you see great results. Nothing wrong that advice, BUT

If you just replace your mix with a mix that has that precise ph good for all elemental availability, you see great results too!

that's why DWC owns. If it's fucked up, you can replace the entire medium-- the water-- instantly, and correct your problems and deficiencies within hours/days, instead of days/weeks in soil.

K.I.S.S.

This is one example where OK advice can be misconstrued to the extreme.

Anyhow, it's probably the ph. Maybe. So many variables. Too trivial of a concern to care at this point, unless you start to see yellowing and serious disfiguring of the leaves.

Adjust the ph, and see if that makes a satisfactory difference!