Apera EC20

[Kimber015]

Hoping someone can help explain this for me.

I have Apera PH60 and Apera EC20, I’ve used the ph reader for a while now and it’s great. I calibrate around every 4-6 weeks and often find it was correct anyway.

With the EC reader I’m a little confused, mainly with converting it to what my feed chart shows, which is EC should be 1.8

My understanding from the picture below is I need to devide my reading which is in us/cm by 700 to get an EC reading. I’ve checked the manual but can’t find where to confirm the conversion rate, as it seems some models use 500:1 and some use 700:1

For example after following the feed chart I get around 1200-1300 us/cm which decided by 700 gives me around 1.8.

The post below does not specifically mention the EC20 model, it’s just the same brand.

Any help will be appreciated.

 

[DrCannaCanadian]

Hoping someone can help explain this for me.

I have Apera PH60 and Apera EC20, I’ve used the ph reader for a while now and it’s great. I calibrate around every 4-6 weeks and often find it was correct anyway.

With the EC reader I’m a little confused, mainly with converting it to what my feed chart shows, which is EC should be 1.8

My understanding from the picture below is I need to devide my reading which is in us/cm by 700 to get an EC reading. I’ve checked the manual but can’t find where to confirm the conversion rate, as it seems some models use 500:1 and some use 700:1

For example after following the feed chart I get around 1200-1300 us/cm which decided by 700 gives me around 1.8.

The post below does not specifically mention the EC20 model, it’s just the same brand.

Any help will be appreciated.

Hi @Kimber015 , great question and I think you are on the right track.

I'm sure you've already researched this, but here is a quick summary just in case:

• ppm stands for parts per million & is the most common domestically used unit when measuring TDS.
• EC stands for electrical conductivity, which is a measurement of the ability of something to conduct electricity. In horticulture, EC is the most accurate way to measure nutrient concentration in solution. Typically, μS/cm2 (microsiemens) is the standard measurement of EC for laboratories.
• TDS stands for total dissolved solids and is a measurement of dissolved salts in solution.
• CF stands for concentration factor and is rarely used professionally in measuring nutrients.
• If ppm is favored, knowing your particular meters’ conversion ratio is crucial to successful crops. Find out from your ppm meter manufacturer what particular ratio is used to determine what the true EC of your solutions may be. Remember, 500ppm to you may be 640ppm or 700ppm to others!

Here at 420 magazine, we have found that there can be a lot of confusion when using ppm because of the different conversion rates.

So, after chatting with @Old Salt , we are choosing to use the more universal measurement of EC, since it is the most accurate way to measure nutrient concentration in solution.

Since you are following the feed chart, and when you divide 1200-1300 us/cm by 700 and it gives you around 1.8 (which is what you want) - then 700 is most likely your conversion rate.

On my TDS pen, if I click the "meas" button - it does the conversion for me automatically.

Anyway, keep doing what your doing - stay in range - and watch your plants closely. Especially the color of the fan leaves - they will let you know if you fall too far out of range by either going light green or dark green.

We hope this helps, and keep asking great questions!