Backyard Aquaponics
A place to discuss aquaponics

Hello all,

what do you think about EC measurement in an aquaponics system? Is it really useful?

This article says that it's useless:

http://practicalaquaponics.com/blog/how ... sick-fish/

Do you agree? Can you tell me your experiences?

Thanks

I measured my EC once, just for novelty value. That was quite a few years ago, so you can probably judge its usefulness in backyard systems from that!

It is a big deal in hydroponics as it can be used to indicate how quickly inorganic nutrients are being used up...
[ EC measures more than just NaCL levels ]

It is also used in controlled aquaculture systems to indicate salt levels.

but not much role in AP....

nitrates will change the EC as will salting a system, but you cant really read much into it during a day-to-day AP system operation. Similar response for ORP meters....

This is what I believe is going on - EC can tell you about the ions in your system water but a lot of the nutrients don't exist as ions in AP, they are bound up in organic molecules which don't have a charge so the EC measurement doesn't really provide useful information about nutrient levels and when you should add. Learn to read the plants and their deficiency symptoms and learn about your indicator plants (the ones that show certain deficiencies first), then you'll have a better handle on what's happening in your system and what you need to do . It helps to know which nutrients are mobile and which are immobile within plants. The most common deficiencies are probably iron and potassium but you'll also see nitrogen, magnesium and phosphorus occasionally and really rarely you might see something else or a toxicity reaction from too much of a nutrient.