First DWC Gow White widow, ice, heavy duty fruity

Nutes question? What Feeding schedual should I be doing?


Eg Seedling EC, Early veg EC, Late veg EC and so on.
I use Hydromino nutes. I have R/O water Ec=.084
My lights are two 14000k ultra blue CFL's

Feels like there growing really slow. ......

The ICE plant i have has grown 2cm in 2 weeks. It is 3 weeks old.
its EC is .736 PH is 6.1 Is this about right? Water temps are between 19c and 24c( I add frozen ice blocks)

The white widow is 10 days old and its ec is 0.560, PH is 6.1

The Heavey duty fruity is a clone 15 days from cutting, EC is 0.729 PH 6.1

The second ICE seedling is 15 days old EC is 0.59 PH is 6.1

No PH down has been added only h2o2 drops every 4 days
The 21 day old Ice plant started to get a purple stem but the last day or so it started turning green again. If that helps.
Thanks for the help guys...

bump^^^^
bump^^^^

Looking good bud!

Hoochy said:

Looking good bud!

Click to expand...

cheers mate

Wish I could help Tanbor, but here in the U.S. we use PPM more.
Europe and Australia are on EC, obviously.
Hopefully someone will come along with the info you need.
Or maybe this will for now :


pH / EC / TDS / PPM
What is the difference between ppm and EC?
Total Dissolved Solids (TDS) is the best measurement of the nutrient concentration of a hydroponic solution. To estimate TDS, one can use a meter that measures the Electric Conductivity (EC) of a solution, and convert the number to TDS in parts per million (ppm). Many meters will do this conversion.

Total dissolved solids (TDS) is typically expressed in parts per million (ppm). It is a measurement of mass and determined by weighing, called a gravimetric analysis. A solution of nutrients dissolved in water at a strength of 700 ppm means that there are 700 milligrams if dissolved solids present for every liter of water. To accurately calculate total dissolved solids (TDS), one would evaporate a measured filtered sample to dryness, and weigh the residue. This type of measurement requires accurate liquid measurement, glassware, a drying oven, and a milligram balance. Example: 50 mL of the 700ppm solution would leave 35 mg of salt at the bottom of a crucible after drying.

Electrical Conductivity (EC) is expressed in siemens per centimeter (s/cm) or milliseimens per centimeter(ms/cm). It can be determined with an inexpensive hand held meter. Nutrient ions have an electrical charge, a whole number, usually a positive or negative 1, 2, or 3. EC is a measurement of all those charges in the solution that conduct electricity. The greater the quantity of nutrient ions in a solution, the more electricity that will be conducted by that solution. A material has a conductance of one siemens if one ampere of electric current can pass through it per volt of electric potential. It is the reciprocal of the ohm, the standard unit of electrical resistance. A siemens is also called a mho (ohm backwards).

For convenience, EC measurements often are converted to TDS units (ppm) by the meter.

The meter cannot directly measure TDS as described above, and instead uses a linear conversion factor to calculate it. Everyone’s nutrient mix is different, so no factor will be exact. The meter uses an approximate conversion factor, because the exact composition of the mix is not known. Conversion factors range from .50 to .72, *depending on the meter manufacturer, which do a good job of approximating a TDS calculation from the meter’s measurement of EC.

* All ppm pens actually measure the value based on EC and then convert the EC value to display the ppm value, having different conversion factors between differing manufacturers is why we have this problem communicating nutrient measurments between one another.

EC is measured in millisiemens per centimeter (ms/cm) or microsiemens per centimeter (us/cm).

One millisiemen = 1000 microsiemens.

EC and CF (Conductivity Factor) are easily converted between each other.
1 ms/cm = 10 CF

"The communication problem"...
So again, the problem is that different ppm pen manufacturers use different conversion factors to calculate the ppm they display. All ppm (TDS, Total Dissolved Solids) pens actually measure in EC or CF and run a conversion program to display the reading in ppm's.

There are three conversion factors which various manufacturers use for displaying ppm's...

USA 1 ms/cm (EC 1.0 or CF 10) = 500 ppm
European 1 ms/cm (EC 1.0 or CF 10) = 640 ppm
Australian 1 ms/cm (EC 1.0 or CF 10) = 700 ppm

For example,

Hanna, Milwaukee 1 ms/cm (EC 1.0 or CF 10) = 500 ppm
Eutech 1 ms/cm (EC 1.0 or CF 10) = 640 ppm
Truncheon 1 ms/cm (EC 1.0 or CF 10) = 700 ppm


Calculating the conversion factor

If your meter allows you to switch between EC and TDS units, your conversion factor can be easily determined by dividing one by the other.

Place the probe in the solution and read TDS in ppm. Change to EC on the meter and read EC in ms/cm.

Conversion factor = ppm / ec.

[Note: ms must be converted to us: One millisiemen = 1000 microsiemens (1.0 ms/cm = 1000.0 us/cm)

According to the chart below:
1.0 ms/cm = 500 ppm (USA Hanna)
1000 us/cm = 500 ppm

Conversion factor = ppm / (ms/cm * 1000)
.50 = 500ppm / (1000us/cm) ]

The answer is your meter's convertion factor and should be a number between 0.50 and 0.72 To improve accuracy, take ec and ppm readings from your res daily for about ten days. Average the conversion factors. The more data points that you use, the closer you will be to finding your true conversion factor.

When reporting your PPM in a thread, please give the conversion factor your meter uses. For example: 550 PPM @0.7 or give the reading in EC, which should be the same meter to meter.

It may also be advisable to give the starting value of your water; there is a huge difference between RO and distilled water with a PPM of approximately 0 and hard tap water of PPM 300 @.5 (notice the conversion factor so others can work out the EC) or well water with a conductance of 2.1 ms/cm.


A note to Organic Growers:

An EC meter has fewer applications for a soil grower because many organic nutrients are not electrically charged or are inert. Things like Superthrive or Fish Emulsion, blood meal, rock phosphate or green sand cannot be measured with a meter reliably when they are applied or in runoff. Meters can only measure electrically charged salts in solution.

"The solution"...
When reporting your PPM in a thread please give the conversion factor your meter uses for example 550 PPM @.7 or give the reading in EC (the EC shoul d be the same meter to meter).






View attachment 1481963

Flo Grow said:

Wish I could help Tanbor, but here in the U.S. we use PPM more.
Europe and Australia are on EC, obviously.
Hopefully someone will come along with the info you need.
Or maybe this will for now :


pH / EC / TDS / PPM
What is the difference between ppm and EC?
Total Dissolved Solids (TDS) is the best measurement of the nutrient concentration of a hydroponic solution. To estimate TDS, one can use a meter that measures the Electric Conductivity (EC) of a solution, and convert the number to TDS in parts per million (ppm). Many meters will do this conversion.

Total dissolved solids (TDS) is typically expressed in parts per million (ppm). It is a measurement of mass and determined by weighing, called a gravimetric analysis. A solution of nutrients dissolved in water at a strength of 700 ppm means that there are 700 milligrams if dissolved solids present for every liter of water. To accurately calculate total dissolved solids (TDS), one would evaporate a measured filtered sample to dryness, and weigh the residue. This type of measurement requires accurate liquid measurement, glassware, a drying oven, and a milligram balance. Example: 50 mL of the 700ppm solution would leave 35 mg of salt at the bottom of a crucible after drying.

Electrical Conductivity (EC) is expressed in siemens per centimeter (s/cm) or milliseimens per centimeter(ms/cm). It can be determined with an inexpensive hand held meter. Nutrient ions have an electrical charge, a whole number, usually a positive or negative 1, 2, or 3. EC is a measurement of all those charges in the solution that conduct electricity. The greater the quantity of nutrient ions in a solution, the more electricity that will be conducted by that solution. A material has a conductance of one siemens if one ampere of electric current can pass through it per volt of electric potential. It is the reciprocal of the ohm, the standard unit of electrical resistance. A siemens is also called a mho (ohm backwards).

For convenience, EC measurements often are converted to TDS units (ppm) by the meter.

The meter cannot directly measure TDS as described above, and instead uses a linear conversion factor to calculate it. Everyone’s nutrient mix is different, so no factor will be exact. The meter uses an approximate conversion factor, because the exact composition of the mix is not known. Conversion factors range from .50 to .72, *depending on the meter manufacturer, which do a good job of approximating a TDS calculation from the meter’s measurement of EC.

* All ppm pens actually measure the value based on EC and then convert the EC value to display the ppm value, having different conversion factors between differing manufacturers is why we have this problem communicating nutrient measurments between one another.

EC is measured in millisiemens per centimeter (ms/cm) or microsiemens per centimeter (us/cm).

One millisiemen = 1000 microsiemens.

EC and CF (Conductivity Factor) are easily converted between each other.
1 ms/cm = 10 CF

"The communication problem"...
So again, the problem is that different ppm pen manufacturers use different conversion factors to calculate the ppm they display. All ppm (TDS, Total Dissolved Solids) pens actually measure in EC or CF and run a conversion program to display the reading in ppm's.

There are three conversion factors which various manufacturers use for displaying ppm's...

USA 1 ms/cm (EC 1.0 or CF 10) = 500 ppm
European 1 ms/cm (EC 1.0 or CF 10) = 640 ppm
Australian 1 ms/cm (EC 1.0 or CF 10) = 700 ppm

For example,

Hanna, Milwaukee 1 ms/cm (EC 1.0 or CF 10) = 500 ppm
Eutech 1 ms/cm (EC 1.0 or CF 10) = 640 ppm
Truncheon 1 ms/cm (EC 1.0 or CF 10) = 700 ppm


Calculating the conversion factor

If your meter allows you to switch between EC and TDS units, your conversion factor can be easily determined by dividing one by the other.

Place the probe in the solution and read TDS in ppm. Change to EC on the meter and read EC in ms/cm.

Conversion factor = ppm / ec.

[Note: ms must be converted to us: One millisiemen = 1000 microsiemens (1.0 ms/cm = 1000.0 us/cm)

According to the chart below:
1.0 ms/cm = 500 ppm (USA Hanna)
1000 us/cm = 500 ppm

Conversion factor = ppm / (ms/cm * 1000)
.50 = 500ppm / (1000us/cm) ]

The answer is your meter's convertion factor and should be a number between 0.50 and 0.72 To improve accuracy, take ec and ppm readings from your res daily for about ten days. Average the conversion factors. The more data points that you use, the closer you will be to finding your true conversion factor.

When reporting your PPM in a thread, please give the conversion factor your meter uses. For example: 550 PPM @0.7 or give the reading in EC, which should be the same meter to meter.

It may also be advisable to give the starting value of your water; there is a huge difference between RO and distilled water with a PPM of approximately 0 and hard tap water of PPM 300 @.5 (notice the conversion factor so others can work out the EC) or well water with a conductance of 2.1 ms/cm.


A note to Organic Growers:

An EC meter has fewer applications for a soil grower because many organic nutrients are not electrically charged or are inert. Things like Superthrive or Fish Emulsion, blood meal, rock phosphate or green sand cannot be measured with a meter reliably when they are applied or in runoff. Meters can only measure electrically charged salts in solution.

"The solution"...
When reporting your PPM in a thread please give the conversion factor your meter uses for example 550 PPM @.7 or give the reading in EC (the EC shoul d be the same meter to meter).

View attachment 1481963

Click to expand...

Thanks For that info.
I have a trunchun and a eutech meters for testing.

Hear are my readings with the trunchun and eutech

Ice 22 days from seed
T=350ppm
E=735u/s
PH=6.2

Ice 16 Days from seed
T=300
E=594

Heavy Duty friuty 16 days from cutting
T=350
E=727
PH=6.1

White widow 12 days from seed
T=250
E=562
Ph=6.2

Hope this helps to see if i'm on the right track. In the photos it goes WW, HDF clone, Ice 16days and Ice 22days

Whats your root developement like? these look like seedlings as opposed to clones, so really they look fine.

The HDF is a clone the rest are from seed.
I was thinking i might be able to put my 600MH watter on soon, once that white widow seedling catches up, might see some faster growth then. Just want to be on the money with the nutes though.

Bonzi Lighthouse said:

Whats your root developement like? these look like seedlings as opposed to clones, so really they look fine.

Click to expand...

Good all are sticking through the netted pots.

ICE 21 days has the most and isin the photo, the rest have only one root poking through.

hi mate i am using big ass net pots 8" by 7" deep after first 2 weeks from seed nothing now there just in there 3rd week an the roots are just starting to come through once they hit the water they will start to explode,
be patient with them, this is first time i used such big netpots an i thought something was wrong but i kept them going an allready i can see massive growth rates, when i use smaller net pots 3-5" size the roots come through quicker an the plant grows faster i had roots in like 5-6 days out the bottom an slurping up its magic juice, but yes these bigger pots seem to keep the roots in longer.
I would say now you can see roots lower the water to about 1/2" to an inch (your call) under the net pot to force the roots out even more to search for that water you might have to get a jug take some water from your res an top feed just for a day or 2 to get them roots in the water but if you have enough bubbles burping underneath your pot you might be ok as hydroton has a slight wicking effect.
I'm only saying top feed as i dont know how much hydrton you have in bottom of netpot to the bottom of your plug root riot/rockwool if you only have about an inch of hydroton inbetween bottom of pot an bottom of your plug you might not need to top feed
for feeding i would do half reccomended dosage see how they like itif its burning jus add a bit plain water if under feeding an there yellowing slightly top it up just my 2 pennies worth m8 peace

Cheers mate see how we go.. I'll up the dose tomorrow seems like there drinking the nutes pretty quick

Actually, if you keep the bottom of your pots submerged the entire grow, you get more feeder roots and less of the thick cord/rope-like search roots.
The air space between the net pot bottoms and the nute solution is what causes the thicker search roots to form.
And the more dissolved oxygen hitting the surface of the soultion, the more feeder roots you'll get too.

Case in point, 3 weeks ago I just harvest 9 ounces from ONE C99 plant in DWC.
Pots submerged the whole time.
The previous 2 grows with air space, harvested almost 6 and 7 ounces each.
Learned that bit of info from Heath Robinson.
His DWC w/ top feed drip rings gets 30 to 40 ounce DRY YIELDS from SINGLE plants !!