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20 days from seed in 20 gallons RDWC ph rises while ppm constant pls help

erwingruber

erwingruber

Member
It is my first run hydro in RDWC and i need some help pls.

20 days old plants from seed with 3-4 roots each submerged in the water 80 Litre(21 gallons).
GH nutes 3 part ( RDWC gh's feeding schedule )
ppm@ 530(.7) constant while ph drifts in 6 hours from 5.5 to 6.0
Very well cleaned clay in netpots + (the rockwool that they germinate)

water temps 23 Celsius(73F)

I think that this is not normal i read from other post's about constant ph or
ec rise - ph down or
ec down - ph up

my case ec stable ph up wthf ??

What i am making wrong , i used 2 ml GH's ph down to bring it from 6,2 to 5,5 and 6 hours later jumbs back to 6,0

How much ph down can i use before it became toxic ?

Pls giv'me some help if you need more details follow link in my sig THNKS !!!
 
C

cyberwax

The first thing i would change is the water temp, its should be around 18,5c optimal, this might very well be the cause of the rise. To maintain a proper waterquality at your temprature you need alot of air and water movement, aswell as a daily dose of h202 and a weekly res change to be safe, i also use a sponge that i pop in the res to give the aerobic bacterias a proper breeding ground. So my tip would be; change the water and keep the temprature at 18-19c.

If you having problems maintaining that water temprature, try mounting a pc fan to the res itself, just mount it above with tubing or whatnot, making sure its light tight, and watch how the temp drops 2-4 degrees celcius. I have made a bucket cooling system that works wonders, let me know if you need the layout, i wonder if windows 7 has the original paint..hmm
 
skotty

skotty

horticulturist
Veteran
mate if your last pic in your grow journal is anything to go by then the amount of roots in your res is not effecient enough to see any major changes.

look at the colour of your res and look at your clay pebbles, they are soaking wet you need to lower that res to at least 1-2" below them net pots to encourage the roots to grow downwards then your problem should sort itself out

just an educated opinion
 
erwingruber

erwingruber

Member
@ cyberwax thnks 4 helping

I use icepacks to cool down my res it is hard work to keep them coming .
Cause i knew that i will have wtaer temp issues i have 20 watt airpumps to my system delivering 1800 Litre / Hour of air in my 80 gallon container it is a hell of bubles in there.
I think i can manage a pc fan in my container but one think is sure it's going to be too wet , how you manage water and DIY electicity ??
Isn't 18-20 celsius the optimal water temps ? as i reading here and there i make the impression that my plants can make it with water temps @ 23 Celsius
I don't know i am confused and i need every help available , i will try to bring my water temp's to 20 Celsius i cannot think someway to waterproof a pc fan how you manage this ?

@ skotty thnks 4 helping

OK. i think you have a point with the water level i will make it lower ,
the color of the res is from GH's Micro bottle my clay is the most clean clay in earth :)
The color of the res is the same before i put the clay inside but indeed i must lower my water level/




(i know that maybe i panic for no reason or that the solution is very easy but hey this all about be a newb !! i am a fast learner)
 
skotty

skotty

horticulturist
Veteran
also just to add to my above post you have no mention of any root stimulator ????

if you do not have any then i strongly advise you purchase something like rhizotonic because plants grown in dwc love that stuff and increases explosive growth in the root zone and it would also explain why your roots at 20 days old are lacking in size ;)


it doesnt matter how many times you wash that clay mate it can still phuk with your ph

peace
 
erwingruber

erwingruber

Member
Yes i know i am lacking in root mass but the ladies is in the system for 4-5 days , before that they handwatered i have some hesi root for hydro but i would like to keep it simple for my first run trying this way to avoid coming alll the time in hydro room yelling for help ;)
 
C

cyberwax

erwingruber said:
I use icepacks to cool down my res it is hard work to keep them coming .

Cause i knew that i will have wtaer temp issues i have 20 watt airpumps to my system delivering 1800 Litre / Hour of air in my 80 gallon container it is a hell of bubles in there.

I think i can manage a pc fan in my container but one think is sure it's going to be too wet , how you manage water and DIY electicity ??

Isn't 18-20 celsius the optimal water temps ? as i reading here and there i make the impression that my plants can make it with water temps @ 23 Celsius

I don't know i am confused and i need every help available , i will try to bring my water temp's to 20 Celsius i cannot think someway to waterproof a pc fan how you manage this ?

(i know that maybe i panic for no reason or that the solution is very easy but hey this all about be a newb !! i am a fast learner)
Click to expand...

No worries man, the reason i try to help out people on this site is not because im an artisan grower or hater, i just enjoy it and its nice to help whereever i can. True story (almost free karma refill)

Well the general rule is that the lower watertemp you have the more oxygen the water can contain, i actually believe the optimal temp is around 15.5c/60f, atleast thats what some of the experts says, im at around 18.4->19.6 depending on how long the lights have been on and im having no issues. No plans to go further down either, why change a winning team etc.

Your dont have to waterproof the fan :D, just mount a fan at one end of a 100mm tube, then insert the other end of the tube into the res somehow*. That way the limit of the distance from the fan to the water will only be limited by the length of your tube. And the fan end can be placed at a cooler spot for more effect. This is not my idea or any fancy shit, its been around for ages to use with aquariums, however a diy is alot cheaper.

*I "insert" my tube by using a bucket with one hole at the bottom for drainage back into the res, and one at the top for the 100mm air tube. Then i have one mister connected to a 1000gph(yea right) aquarium pump that continuously pumps water, i have the other end of the air tubing semioverlapping the intake so air is blow down into the bucket, i also have another hole at the top for the air to escape through. This way i avoid the usage of any termostat controlling the pump as the intake is only on during lights. Its not pretty but it works.
 
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erwingruber

erwingruber

Member
you are the man !!!
So simple to do , but i did not even imagine it my other problem is to draw cool air from somewhere but i will manage , unfrontunatly i have general temp issues with my growcloset
and i cannot beat them , only way to build somewhere else and this is going to happen soon !!!
(to give you something for example last run finish in August just for fun....... with 35 celsius , 95F ambient temps you do not want to know canopy temps but the weed make it .... little bit fried)
 
C

crazybear

Member
it also may be your not adding enough PH down I was running into the same problem with tap water, I am new to growing in hydro dwc , and I would add a little because it dosen't say on the GH brand PH down to add.
 
C

cyberwax

crazybear said:
it also may be your not adding enough PH down I was running into the same problem with tap water, I am new to growing in hydro dwc , and I would add a little because it dosen't say on the GH brand PH down to add.
Click to expand...

The ph down effect you describe is your plants craving nitrogen wich the ph down usually contains alot of, and i would advice using a grow nute to stabilize that, ph down should be applied as little as possible. However when i replied to this i replied to the first error i saw, the water temp, you might aswell be underfeeding as i have seen no pictures yet :p (i saw someone commenting as if they had seen a picture so i will be looking for that)

However if your intial tap water(if thats what ur using) ph is higher than your grow ph and your res is huge the ph might be affected alittle before a noticable ec drop depending on measuring eq, meaning if you have a bluelab truncheon(spelling?) with the group numbers it would be harder to notice compared to a digital ph meter.

But enough speculations; another golden rule here is that when plants grow/especially bloom they use one part mineral(nutes) and release one part acid and that wouldnt raise ph, hence my initial water culture suspicion statement.

With flowering greetings,
cbrwx
 
D

dancer

Member
Do not drop your water level below the netpots! Dont leave a gap there.
It is not correct, it makes no sense and it's a waste of space.
Not dipped halfway in the water either, around inch deep.
 
M

morrisgreenberg

Member
theres some disagreement latley about the issues of x-planting rootling and leaving a gap between netpot and water line. if you have roots dangling you can and should do this, especially if you run a bubbler or RDWC, need not worry ROOTS are SCAVENGERS, you will encourage them to grow into the water, the young tender roots will thrive in the chamber that is 100% humid, and if running tru deep water culture your air pump will provide the bubbles that will splash onto the roots, the whole reason why i recommend this is because of the use of Rockwool and peat pucks, i hate having this media always soaked, young rootlings will be dependant on a nice moist oxy rich media, not water logged rockwool
 
M

morrisgreenberg

Member
But enough speculations; another golden rule here is that when plants grow/especially bloom they use one part mineral(nutes) and release one part acid and that wouldnt raise ph, hence my initial water culture suspicion statement.

With flowering greetings,
cbrwx[/quote]

i would like to concur with this statment , but in another light. i have been told by certain horticultural PHd's on another forum that the key to PH flux is nitrogen usage, on a daily basis during Veg the plant is consuming plenty of nitroegn right? well as she consumes the water chemistry changes, im no chemist so i cant describe it perfectly, but the PH rises from this, spent NItrogen turns into another element dont remember. this is why we tend to have a much more stable PH during flower, we artificially deprive the water supply of Nitrogen and the plant takes up less on her own. the poster before my post is dead on, 6 is good enough ...DO NOT LOVE YOUR PLANTS TO DEATH!
 
erwingruber

erwingruber

Member
Ok here is my updates ph from 5.5 to 6.3 in 20 hours
As my first step i lower the water level about 1 inch - 3cm from net pot removing 20 litre - 5gallons of water , i will try make the DYI pc fan blowing over the water level.
I add 1 ml of GH's ph down and bring the ph reading from 6,3 to 5,9 and i am waiting the response from the system , i will keep you updated , Really how much Ph down is a lot of ph down in ml per litre .

here is a pic from the inside of the tank before and after lowering water level

picture.php

picture.php
 
Japanfreakier

Japanfreakier

Active member
Veteran
6.0 is a little high but still within acceptable range really, I wouldn't worry about. Within 5 days you'll be able to up the strength and the pH will be more stable.
 
Japanfreakier

Japanfreakier

Active member
Veteran
I've never readjusted my pH. In dwc I've always set it low and let it raise up and once it's out of range dumped and remixed.
 
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