Few understand ec meter relationship with ph meters, and why its so crucial to measure both to get the true reading your looking for your electrical conductivity meter or ppm value, so here’s my guide.
Your guide to e.c meters and also the relationship with ph meters isn’t immediately obvious relationship at first, which is why I’ve written this guide in order to better explain electrical conductivity, it’s limitations and it’s uses.
What’s electrical conductivity
ec meter testing Ec meters as you’ve probably already worked out measures electrical conductivity of your water, this measurement is taken my measuring the amount of impurity’s – dissolved salts by the resistants they course within the water spoliations
The more dissolved salt content within the solution the essayer it is for a electrical currant to pass though, i.e. less resistants and more conductive, just like a home current meter does, except electrical conductivity meters have an algorithm within a chip that works out the reading you want.
Why use ec meters
It’s very useful for hydroponics because the conductivity of a solution is proportional to the amount of salts “in this case the salts are our nutrients” dissolved within your nutrient solution; so, if a solution has more salts dissolved, it has a higher conductivity. Therefore, measuring EC can give you an idea of how many nutrients are left in your solution.
Ec meter readings
Although electrical conductivity meters give you a very good idea of the strength of nutrient solutions, they can never be absolutely true, for one reason, resolved salts (nutrient) have different ions, that each have their own specific conductivity (they contribute differently to the overall EC) so you could in fact be deceived because you could just have a small amount of an ion that conducts to much or to little
Ph and ec meter relationship
ec meter and case Ph of water needs to be constant from one day to another if you want the most accurate ec reading possible, “after all you’ve gone to the expense of buying your meter” this is because the acids and alkalines have a conductivities hundreds of times larger than other ions. So water that has a ph reading, lets say six on a Monday, and then strait after you measure the conduciveness, and that says, lets say 2000u/S, then three days later you do the same, except your ph value has now changed to seven, alto this time you’ve not measured the ph, so this you don’t know, so because the ions that determine ph values have a large affect on ec values making a comparison form one day to another meaningless.
So what’s an ec meter good for then.
The electrical conductivity can tell you have much nutrients your plants have taken out, from the last time you measured or how much water has been used or evaporated, but what I cant tell you which nutrients your plants have used, and others they’ve left.
If your solution becomes to higher value by either water used or evaporated, you can correct by adding more water to lower it back down to the original value.
When ec measurement falls as your plants use up the nutrient you may be tempted to add more of your nutrients until the original value returns, please don’t be temped as this will cause the solution to become toxic for your plants, and at best will cause nutrient deficiency’s, as plants don’t use all the dissolved salts equally, leaving some to slowly build up to toxic levels.
When to change your Water solution
After your solution has been used for one week, check you ph first, and adjust, then test your ec value and if it high, just add water then adjust your ph and test the ec solution again, if your reading shows the values a little low, say by 10% add more nutrient, and leave your hydroponics system “time between checking depends on how large your reservoir is, how hot the environment is and how large your plants are” after you’ve replaced either water or nutrient or both for the second time, its best to replace nutrients solution with a fresh batch, and use what’s left for your garden watering.
Too hot too cold
Temperature will need taking into account if your ec meter does not have ATC (auto temperature compensation) this you can do by either checking the temp and adjusting before a reading can be make or the easiest way, which is to test your solution at the same time of day each time