How do I use my EC pen?

[faceless42001]

Hi, I read this:

A generic baseline approach would be the same as hydro. Just like in a DWC setup, start feeding around two weeks after sprout with about 150-300ppm. Do this every-other watering and watch your plant. If she looks hungry, try feeding nutes-nutes-water. If she looks over feed try nutes-water-water. You get the idea. You have to dial it in, and every plant you grow may be different. Increase to 400-600ppm after a few weeks, then eventually up to 800-1000ppm. I rarely go over 900ppm. Coco likes frequent low does feedings, but you can hit them hard when needed. If you over do it a flush should get you back in good shape.

But I don't know how to calculate PPM with my EC meter. Please tell me the calculation.

This is the EC pen I have:

 

[Stanovich420]

There might be slight variation,but think it's close enough

 

[faceless42001]

So if my pen says 2.0 then I know the water is 1000ppm to 1400ppm, not very accurate but it'll do I suppose.

 

[BuddroGreen]

You calculate the EC x either 500 or 700 to get TDS/PPM. If you have an EC of 1.4 you would multiply 1.4 x (scale 500) = 700 TDS/PPM, same for the other scale.

Nutrient manufacturers use different scales (.5 or .7) for their nutrient formulas. EC is the true value and TDS (total dissolved solids)/PPM (parts per million) are the converted value from either .5/.7 scale depending on what type of TDS/PPM pen you're using.

If you bought a TDS/PPM pen it would do the conversion for you from EC on the scale the pen is set up for either .5/.7

 

[faceless42001]

I'm using coco coir, do you know the scale for that?

 

[Weaselcracker]

EC is EC, and you should get the same reading on a given solution, whichever EC tester you use.
There is no way to directly test Ppm. A 'ppm meter' only, and can only measure EC. It then multiplies the EC by a 'conversion rate' number to estimate ppm. For some reason manufacturers use different conversion rates to guesstimate the PPM. The common conversion rates are .5, .64 and .7
That's what that chart is about.
This means that if someone tells you to feed your plants at 1000 ppm, the information is not very helpful unless you know what conversion rate is used, and your conversion rate, and can then compare the two. Whereas if they had told you the EC you know immediately what level they are feeding at.
However since most of the time you only need to know EC or PPM in relation to your own feeding schedule, it often doesn't matter. Usually what you want to know is that whether you are feeding the plant slightly less or slightly more compared to what you did the week before, or the month or year before.
I hope this makes sense and I haven't wasted my precious time typing this. Ha ha
If you want to know the conversion rate of your pen you will have to get that information from the manufacturer. That is to say- its probably on the Internet

 

[BuddroGreen]

I'm using coco coir, do you know the scale for that?

Your coco has nothing to do with the scale conversion

seedlings with three sets of true leaves & roots = EC 0.5-0.6
Veg = EC 0.6-1.2
Bloom = 1.2-1.6 (Max 2.0)

That's what I use throughout an entire grow, slowly raise the EC of the nutrient solution as they grow and max out at week 5-6 of Bloom (8 week strain) and slowly decrease EC for flush, and 5.8pH in coco, and water lightly everyday and as they get bigger they will require 2-3 light feedings or 2 heavier feedings a day to 15% runoff.

 

[ert3tyyhr]

I use coco and run 1.1 to 1.3 veg and as high as 1.4 to 1.6 bloom. Ec coco needs a bit lower ph more like 5.8 or 5.9 and as is very hard to over water in coco just a small amount of control on how often and how much learn your plants and feed them what they will take I grow with veg at 3 times a day but I am ebb and flow. Remember to read your water before you start and deduct that number before your start. mixen nutrients the temperature of your h20 is important and the word ph should be your first question. I started with ppm meter because you can monitor the quantity of your nutrients much better as you mix them and for beginners is a good way EC will also change with the nutrients but most of the industry tells you ppm. After all these years I use both If you guess wrong with nutrients you will burn plant it can recover with a good flush if you PH shock them they are stunted they will finish out but be stunted in size and will taste funny and is no curing process will change that taste. PH shock in extreme cases will cause nutrient lock out and then nitrogen toxicity. How ever you do it if you make a mistake make it on the lower side of the number and you will be fine and remember to ph the plant run off and match that ph with the flush.

 

[faceless42001]

I found this in the my instruction leaflet, does it help with the conversion scale? Thanks for that advice hermit, if I can't figure out my conversion scale I'll do what you do.

 

[Weaselcracker]

It means that your pen uses a conversion rate of .700, which admittedly is fairly plain to see if you look at the numbers there.

 

[KingJames]

I'm going to keep a eye on this thread, as I'm think about geting a ppm meter, and would like to know more about them, and how to use them

 

[faceless42001]

Alrighty then so it's as simple as multiplying the number on the pen by 700 to get the PPM, cool.

KingJames, get a PPM pen instead of an EC pen and you shouldn't have to convert it manually.

 

[KingJames]

Alrighty then so it's as simple as multiplying the number on the pen by 700 to get the PPM, cool.

KingJames, get a PPM pen instead of an EC pen and you shouldn't have to convert it manually.

Is there certain brand that works better, or that is eaiser to use.
I have seen soon really inexpensive one on eBay.
Thank you in advance for your input

 

[faceless42001]

I don't know any brands, I'm brand new to this, but if you get a PPM pen it will save you manually converting, it's not that big of a deal though just a simple little sum.

As for a brand hat works best (someone please correct me if I'm wrong) I would assume the more you pay the better the pen will be, but I have a fairly cheap one and it seems to work fine.

 

[ert3tyyhr]

I like Milwaukee mostly because I have both PH and EC by them but you need to calibrate it every month or so. My advice to most of these type of question read and read and then read more there people who have already answered these questions. I use a ppm meter to mix the nutrients for me I have a 25 gallon ebb and flow and two 20 gals. The last is the EC and final PH. I keep track of every reading and compare the ppm and EC the differences you will see is the water you use. If RO the filter fades after a lot of use and the PPM will go up so I use the before I use it test then Mix. I didn't waste my money on the supposed super nut's like canna and the rest is overpriced you’re paying for water and fancy labels. I mix Jacks to the ppm one at a time in two jugs and this is not rocket science but close counts in horseshoes, hand grenades, politics (which is like tiddley winks )here I uses a gram scale and measuring devices that are very accurate. After time you no to the gram how much to add. If you believe all the hype about names I will not mention except canna I grew with it for years and now I use jacks and spend penny's for what cost 100's oh and some molasses or raw honey. Was it as good as canna well not the first two times was very close but the yield was 8 to 10% less but the taste was worth it if you think flushing something you have been adding for 30 to 45 days veg. and 6 to 8 weeks bloom is going to flush out in 10 to 14 days (I have a slightly used bridge in NY cheap I will sell you) The taste alone makes it a better deal and no tips burning and no problems with deffiencys. I still have problems with heat and light burns but that is because I live where its over a 100 for over 100days. More A/C. You must remember that this is more or less mother nature’s game and for several million years weed has grown in this country. Long before the get rich quick guys got involved, now I would like to know how the super science growers think they are growing just what they eat chemicals that make food better and they believe that makes the weed better will be just like the food most of you eat. Chemistry. Why pay 100's for what you can buy with Pennies. Where is this going I have cows and horses and chickens next year this time I will be using compost teas I just don't have the numbers right. For now I use Jacks, and coco, perlite, RO H20, when I change out my reservoirs which is weekly it costs 14.00 (for all of them). There were no forums when I started and most of what I know I read in Book’s and talking with other grower’s.

Composted tea's don't smell badly when aged right and to me, smells like money.

No Pictures its evidence and once you post the picture on the internet is public.

The measurements are on the jug you will have to adjust to your situation. In some cases you will have to add salts but as Jacks is a chemistry thing, with less, in old days had nine or ten bottles now have 3. It took months and several grows but my weight is about the same or just a little better. Remember this California made them stop selling several things that were really bad but none of them will tell you what is in them. That is like our government just pay and this is the very best better than the Rest. When you start with your brain and wallet you will spend 100s even 1000s. How many have spent the 30 or 40 bucks had your water tested then everything is known. After having the water checked thru co-op I learned they change with the seasons many hear are having little problems. They jump on the chemistry thing. Ground water change when you have a drought and then a big bunch of rain 21” I told them to retest the H20. I got an RO filter was all the difference and El Ninyo is a big long flush of the ground and into the water table.

One more thing about meters YOU get what you pay fore I buy the middle priced ones and check them monthly

More typing than I have done in a very long time am old man who rambles and English I was a football player.

 

[BuddroGreen]

I use a HM Digital TDS-4 about $16 on ebay or amazon...it uses the (.5) conversion, don't forget calibration solution and use (NaCl) calibration solution with that TDS pen I mentioned.

 

[Ray Relic]

Trouble with an inexpensive pen, you end up buying a second one to verify the first. Thereby spending as much as you would have on a good one you had confidence in.

I'm a total newbie, but I think a person should focus on EC readings. Learn those values, they're the universal language. And the Chart above, get a printout, it's a constant good reference as you practice.



And remember to add in your source water values.