Following PPMs for under/overfeeding warnings

[Death The Cultivator]

Thank you! And yes, looking at the ppm is just one part of the larger equation, I have read tons of literature on the subject and probs watched hundreds of hours of videos at this point but some things like ppms ppl never seem to get into the nitty-gritty numbers with and only give a sky level overview so it had been maddening trying to dial this specific metric in.



I am sorry but this is just flat wrong. Professionally I have worked with million dollar lab equipment doing QA tests for my job and even those testers have a small percent plus or minus variance for any measurements. The stuff we would use for gardening certainly is not more accurate than that type of equipment. Even beyond the accuracy threshold of the meter, ANY non-static solution is going to have small pockets of higher or slower salinity/ph/temp/literally anything else. There is no such thing as a "perfect mixture" - the variances may be small but they are there.

At the top of this post you can see how to answer the question, it is a very simple question to answer when you don't try to turn the question into more than is being asked. If you are unwilling to give a straightforward answer then NOT ANSWERING AT ALL is a valid option that I encourage you to take.

I'm glad you got the answer you felt you were looking for.

 

[JoeCollins]

I'm glad you got the answer you felt you were looking for.

I got /an/ answer, but one persons assessment of how they read ppms is not truly "the" answer. who is to say if their assessment of the threshold is correct? That is why I posted on the forum publicly instead of just messaging someone privately, bc I am looking to hear multiple opinions - and I would like you hear yours too, if you would actually provide it.

 

[Bill.de.Cat]

Some lovely help y'all, much useful input. So glad I reached out for help. 0/10 would not recommend.

A lil bit harsh there don't you think......I mean you could get all kinds of answers, even I could post about it...mine would be all wrong as I only do soil type growing so I kept my thoughts to myself.....but if your out for answers only instead of good answers......

 

[JoeCollins]

A lil bit harsh there don't you think......I mean you could get all kinds of answers, even I could post about it...mine would be all wrong as I only do soil type growing so I kept my thoughts to myself.....but if your out for answers only instead of good answers......

I mean the post only sat for 3 weeks with one reply that did not address the question being asked. I am not pushing for any answer regardless of correctness, but no answer at all is equally as unhelpful.

 

[Bill.de.Cat]

I mean the post only sat for 3 weeks with one reply that did not address the question being asked. I am not pushing for any answer regardless of correctness, but no answer at all is equally as unhelpful.
True, it sat for a while, but a simple "Bump" or " Is thing thing on" works too.....but to each their own..cheers

 

[Death The Cultivator]

I got /an/ answer, but one persons assessment of how they read ppms is not truly "the" answer. who is to say if their assessment of the threshold is correct? That is why I posted on the forum publicly instead of just messaging someone privately, bc I am looking to hear multiple opinions - and I would like you hear yours too, if you would actually provide it.

You would have gotten it if you answered the questions, it's not a cut and dry situation to give you a definitive answer. At the very least EC will remain very stable in a reservoir that is circulated so any drift needs to be determined based on the specific situation. Are we dealing with some nutrient precipitation/tap water/temps/feed chart issues/etc.

For me, when I run recirculating systems I'm looking for deviations of 1.0ec or more but the reservoir is going to be topped up with 50% strength. If you're properly mixing your reservoir, following the feed chart from the manufacturer, and keeping your res under 72f I can't imagine any problems unless there's a ton of algae.

 

[JoeCollins]

You are still trying to diagnose a WHOLE issue when I am simply asking what number change would you need to see on the meter that would register to you as "Ok my ppms have dropped" that's it, point blank. Not what that fact would mean for the larger plant health or what you would do to fix it, just simply making a mental note that ONE THING OF THE LARGER PICTURE to consider is a lowered PPM. Only thing you said on point was this:

For me, when I run recirculating systems I'm looking for deviations of 1.0ec or more

Now 1ec is ~500 ppm, 500ppm of a 900-1200ppm solution is a pretty large drop - especially when you are preaching such stability. Maybe I am misunderstanding but this sounds more like a growing strategy rather than your measuring methodology. Not trying to argue bc with what you gave we are making progress, but waiting for a 30%ish drop in concentration seems a bit steep - in other words you say 500 is your threshold, but if my ppms dropped 300pts (0.6ec or so?) I don't think I would see that as "stable" - but maybe that is where I am going wrong and why I am asking these questions.

 

[Death The Cultivator]

You are still trying to diagnose a WHOLE issue when I am simply asking what number change would you need to see on the meter that would register to you as "Ok my ppms have dropped" that's it, point blank. Not what that fact would mean for the larger plant health or what you would do to fix it, just simply making a mental note that ONE THING OF THE LARGER PICTURE to consider is a lowered PPM. Only thing you said on point was this:



Now 1ec is ~500 ppm, 500ppm of a 900-1200ppm solution is a pretty large drop - especially when you are preaching such stability. Maybe I am misunderstanding but this sounds more like a growing strategy rather than your measuring methodology. Not trying to argue bc with what you gave we are making progress, but waiting for a 30%ish drop in concentration seems a bit steep - in other words you say 500 is your threshold, but if my ppms dropped 300pts (0.6ec or so?) I don't think I would see that as "stable" - but maybe that is where I am going wrong and why I am asking these questions.

I'm trying to make the point that by mentioning what you believed to be me diagnosing is what gets me to the point where we're talking about a 1.0ec drop.

A 1.0 drop or increase from say a 2.4 or 1.5 is concerning in a recirculating system. So if all that other stuff is in check then I can assess plant health to make a final decision on the change in EC.

Between several EC meters the deviation is only .1ec plus following nutrients manufacturers charts I have a standard EC that I should be hitting. I'm checking for precipitation, if there is none and the reservoir isn't too warm - I'm dumping it and remaking the solution rather than just topping it up with 50%. I'm not waiting for a drop, it should happen naturally in a recirculating system but in a drain to waste system it should stay at whatever EC I started with or something is wrong and the reservoir needs to be dumped.

If I make a 55g barrel of 2.4 ec water it should be 2.4 every day I check, pH may drift but the EC should remain stable with a pump circulating. If everything is as it should be the EC won't change unless you're in a recirculating system.

 

[JoeCollins]

I'm trying to make the point that by mentioning what you believed to be me diagnosing is what gets me to the point where we're talking about a 1.0ec drop.

A 1.0 drop or increase from say a 2.4 or 1.5 is concerning in a recirculating system. So if all that other stuff is in check then I can assess plant health to make a final decision on the change in EC.

Between several EC meters the deviation is only .1ec plus following nutrients manufacturers charts I have a standard EC that I should be hitting. I'm checking for precipitation, if there is none and the reservoir isn't too warm - I'm dumping it and remaking the solution rather than just topping it up with 50%. I'm not waiting for a drop, it should happen naturally in a recirculating system but in a drain to waste system it should stay at whatever EC I started with or something is wrong and the reservoir needs to be dumped.

If I make a 55g barrel of 2.4 ec water it should be 2.4 every day I check, pH may drift but the EC should remain stable with a pump circulating. If everything is as it should be the EC won't change unless you're in a recirculating system.

there you go wildly off topic again

 

[Death The Cultivator]

there you go wildly off topic again

Good luck finding the answer to your query. May the Canna spirits guide you.