- Thread starter
- #641
Dude, I need to be able to grow a plant to completion before I start doing that crap. I'm sure I will at some point but that will be FAR FAR FAR down the road.
Alaskan1's Flo n Gro Mixed Bag Grow
- Thread starter Alaskan1
- Start date
Dude, I need to be able to grow a plant to completion before I start doing that crap. I'm sure I will at some point but that will be FAR FAR FAR down the road.
Might want to turn down the ppms, or keep a real close eye on them. With .5 meter that's 3.26 ec. purty high. Even advanced nutrients highest ec is 2.85 at peak.
If it's a .7 meter the ec is 2.32 and fine.
- Thread starter
- #643
I was incorrect it's .7
How is TDS measured?
By means of a conductivity meter. The conductivity is measured and the TDS is calculated by a fixed mathematical formula in the meter. Back To Top ^
What about conversion factors?
Research has shown that a conversion factor between .64 and .70 to be the best indication of Total Dissolved Solids in growing applications. Back To Top ^
If I have a TDS meter with a 0.5 conversion factor how do I convert to the correct 0.7 value?
Multiply by 1.4; ex: 500 x 1.4 = 700. Back To Top ^
What is the difference between microSiemens (µS) and milliSiemens (mS)?
Both are units of conductivity. 1000 microSiemens (µS) = 1 milliSiemen (mS).
Back To Top ^
How do I convert between milliSiemens (mS) and ppm?
Convert to microSiemens by multiplying by 1000. Then multiply by 0.7: ex. Your reading is 2.14 milliSiemens (x 1000 = 2140 microSiemens). 2140 x 0.7 = 1498 ppm. Or simply multiply by 700. (2.14 x 700 = 1498) Back To Top ^
What if I want to switch to EC measurements?
If you do not have a meter which reads both in EC and TDS you may prepare your fertilizer solution according too the directions given and take the EC reading. This will be your value. Or, consult with the manufacturer of your fertilizer for the correct EC readings for that particular fertilizer. Back To Top ^
What is the relation between electrical conductivity (EC) &
dissolved solids (TDS)?
Though there is a close relationship between TDS and Electrical Conductivity, they are not the same thing. Total Dissolved Solids (TDS) and Electrical Conductivity (EC) are two separate parameters. TDS is the combined total of solids dissolved in water. EC is the ability of something to conduct electricity (in this case, water's ability to conduct electricity).
The only true method of measuring TDS is to weigh residue found in water after the water has evaporated. You know those spots you see on a glass after you wash it and let it air dry? That's TDS! That residue has mass, and it's possible to weigh it, but if you're not in a lab, it can be tricky thing to do. Therefore, we can estimate TDS levels based on the conductivity of the water since the hydrogen and oxygen molecules of the H2O carry almost no electrical charge. The EC of most other metals, minerals and salts will carry a charge. A A TDS meter measures that EC level and then converts it to a TDS measurement. Since different metals, minerals and salts will be more or less conductive than others, there are different conversion factors that can be used.
ppm (parts per million) is the most commonly used scale to measure TDS (Total Dissolved Solids).
µS (micro-Siemens) is the most commonly used scale to measure EC (Electrical Conductivity). Back To Top ^
I just want to verify that Hanna uses mostly .5. and strengthen the fact that 3.26EC is super high. Top off with some pure water.
My three Hanna's are all .5....if that helps.
- Thread starter
- #646
That information I just posted was off of Hannas website. If what they are saying is true that a conversion factor of between .64 to .7 is optimal then why would they have their meters at .5??
And, don't all meters convert to PPMs just using a different conversion to get to the same place?
- Thread starter
- #647
I'm using Technoflora and they say my PPMs should be at 1430.. Right now my water out of the tap reads 145 so if you deduct the 145 from the 1515 I currebtky have am I not in the ball park?
That is the same question I asked. . . They say that .63 to .7 is most accurate, but the make a lot of their meters (except the most expensive) at .5... makes no sense.
All meters measure EC: Electrical Conductivity... The CONVERSION factor varies by make from .43 to .75
There is no ACTUAL way to tell the PPM and all meters do is give a rough estimate based on conductivity since absolutely pure water conducts no electrical charge at all.
This in mind, I have since gotten a true EC meter, and am done with PPM estimators.
ALSO, the manufacturer of the nutrients could be measuring on a .75, .70, or a .63 meter and your .5 meter will be off... and visa versa... I look for EC now instead of PPM.
SmokzAlot
New Member
Great topic, but in the end to me its only a go-no-go gauge. I observe the plant as the final gauge. Growing is a multitude of components that must serve a common goal. Going strictly by the numbers has never been my style. Kind of like cooking, a tweak here and there and its all good. Least not forget there is always more than one way to get there.
The best they do for me is to let me know where I am at with a given condition. I still must decipher the data and decide a plan of adaptation. This all goes along with "K.I.S.S." and "Dont Fix it if it ain't broke"
The best they do for me is to let me know where I am at with a given condition. I still must decipher the data and decide a plan of adaptation. This all goes along with "K.I.S.S." and "Dont Fix it if it ain't broke"
- Thread starter
- #650
My meter (get this) has a variable conversion factor based on what TDS calibration solution I use. can be anywhere from .56 to .78 lol
I think I will start using the EC selection on my meter!
- Thread starter
- #651
My plants show absolutely no signs of nute burn at all. They look pretty damn happy and healthy. They aren't as dark green as I'd like them to be but I think I will add a little nitrogen to the mix next res change.
keep in mind that TDS is TOTAL dissolved solids... there is no way to tell WHAT those solids are... just go by your mixing chart, and adjust as needed if your plants show signs. EC is really to check after a week or so to see how they are taking up the nutrients or if there is a pH problem to rule out a water soak-up happening and causing the pH to fall rapidly below 5.2, or hungry plants removing the nutes and leaving the water causing pH to spike to 6.1+. Otherwise, it's really not something to keep tabs on constantly.
- Thread starter
- #653
I check daily.
My PH goes up slightly everyday. I knock it back down. The reason my PPMs are so high is I added H202 and some hygrozyme to the mix. After this res I won't be adding those again until the grow is complete. The roots are really looking fantastic this go around.
I really appreciate the info jandre and Smokz!
My PH goes up slightly everyday. I knock it back down. The reason my PPMs are so high is I added H202 and some hygrozyme to the mix. After this res I won't be adding those again until the grow is complete. The roots are really looking fantastic this go around.
I really appreciate the info jandre and Smokz!
SmokzAlot
New Member
Together we are better than any one of us alone.. I learn, you learn, we all learn.
bunch of u guys in here should have a science degrees with all the technical stuff thats going on
i remember back in the day just throwing in a pot with some soil mixing with certain aggregates throwing some worms in using egg shells and shit and just letting it grow outside
now its so scientific
its just amazing how much this weed has evolved with the science involved
i remember back in the day just throwing in a pot with some soil mixing with certain aggregates throwing some worms in using egg shells and shit and just letting it grow outside
now its so scientific
its just amazing how much this weed has evolved with the science involved
- Thread starter
- #656
Together we are better than any one of us alone.. I learn, you learn, we all learn.
Damn straight on that one my friend! ! ! ! !
SpaceGhost
New Member
Ok so I just checked my meter and I was using the 500 conversion. Should I be using the 700 conversion? Wow if so I've been over nutin since day one?
nuts veg room 1580 by 700 conversion
flowering room 1340 I just changed reservoir and was running on the low side for the 1st couple of days till it balanced out
I am using a blue labs ppm pen
Before I read any further, the question to ask is "at what conversion factor is the 1430 ppm referenced?" I guarantee it's .7 which is slightly over 2 ec and acceptable.
So if using a .5 meter we would be at the same ec at 1000ppm. EC is the true important number as such. We always refer to ppm though.
Since learning about this I have made it a habit to state my ppm as: 980 ppm (.5 conversion). for example.
This way a person here using a .7 meter could easily do the math and see I would be at almost 1400 ppm on his meter. Now we're starting to speak the same language and can offer better qualified responses.
I wouldn't worry about the fact you have a .5 meter. Lots of folks do. And they work fine in their grows. I really dont think it's that important it needs to be .64-.7 conversion or whatever they said. So long as we use the conversion factor properly.
- Thread starter
- #660
You should read your owners manual or go to their website to find out what conversion factor they are using to calibrate the ppms
pH Meter – pH conductivity - digital conductivity meters
blue labs website