I recently got a PPM meter that checks EC CF and PPM (700 scale) and TDS calibration solution that is 342 and 1000 ppm. (I am pretty sure it converts to 700 scale. I am at .86 EC currently and 600 ppm.) The solution does not actually say what PPM scale it is on, but says NaCl on it which makes me think it is calibration solution for a 500 scale ppm meter. So my question is what is the EC (Cause I can calibrate that) of NaCl TDS calibration solution 342 ppm and 1000 ppm? The 1000 should be an EC of 2.0 right? I am going to get a blue lab monitor for my res but want to get this straight while I wait for it. This is the calibration solution I am using https://www.amazon.com/HM-Digital-C342-Calibration-Solution/dp/B001VE99X8/ref=asc_df_B001VE99X8/?tag=hyprod-20&linkCode=df0&hvadid=167138399519&hvpos=&hvnetw=g&hvrand=12830387075903049010&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1026748&hvtargid=pla-307836974550&psc=1
TDS meter
- Thread starter Gambit79
- Start date
70's natureboy
Well-Known Member
The solution is absolutely correct and your meter is supposed to read it correctly. I use the 1300 ppm and it is always 1300 ppm no matter what your meter says. That's how you know how to read your meter. The Truncheon stick is so nice because it displays all scales.
rkymtnman
Well-Known Member
looking at that label of the 342 bottle , the EC (in micro siemens: the funny looking mS) is 0.7EC
Thanks! I thought it was, just wanted to make sure. When calibrate it to that EC the PPM came out as 480 (which obviously didn't match the bottle) and that is how I discovered my PPM meter was 700 scale, and why my plants PH was falling (I was underfeeding)
rkymtnman
Well-Known Member
on the bright side, your meter is accurate. lol.
stick with EC. don't use ppm and you wont' need to know if your meter is 0.5, 0.7 or there is one other weird conversion. EC is EC.
You don't need your meter to be calibrated to know you are underfeeding. PPM fall, underfed. PPM rise, overfed. Unless it is wild swinging in which case you have buildup/lockout.
Same as you don't really need to do what the bottle says, on anything. Half everything it says on a bottle and don't care what ppm it says, just watch and see if it climbs or falls.
Use your ppm as a reference only with yourself. ie. what your own solution was yesterday vs what it is today. You shouldn't compare your ppm with anyone elses.
Same as you don't really need to do what the bottle says, on anything. Half everything it says on a bottle and don't care what ppm it says, just watch and see if it climbs or falls.
Use your ppm as a reference only with yourself. ie. what your own solution was yesterday vs what it is today. You shouldn't compare your ppm with anyone elses.
Guardians FTW!
I usually keep it at 1.0 and 1.2 EC. The problem was it was a new meter that I calibrated wrong so when I thought I was at 1.0 I was really at 0.6 Plants aren't having any issues because I caught it fast, but EC wasn't going down either, just PH falling. I don't follow any bottles beyond the ratios. I think I didn't see the PPM drop because of the calibration being so off. These plants are on week 9 of veg, and just starting flower today so they are hungry. Strawberry cough Mainlined for 8 colas.
