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[on:]

Hi,

Does anyone know of a module that will detect the amount of nutrients in a water solution? This is for my hydroponics setup at home. I want it to be fully automated to introduce more fertilizer in the system when nutrients are depleted.

Thanks!!!

[Reply #1 on:]

I read this urban farming post a few weeks ago: http://hackaday.com/2012/06/27/urban-farming-uses-aquaponics-to-make-farmland-where-there-is-none/

[Reply #2 on:]

The simplest method is to buy an off the shelf sensor for that purpose and "connect" it to an Arduino. Attempting to design and build that type of sensor is not a trivial job, not at ALL trivial. The alternative is to assume a certain amount of use and replace the "estimated' depleted chemicals (the real commercial method that I have seen and used in designing irrigation control equipment). The first method is by far more accurate, the second much more practical (and much less expensive) but it does have it's drawbacks... Care is recommended especially if your "Crop" is valuable or difficult to obtain by non horticultural <BG> methods... IMO

Doc

[Reply #3 on:]

This should do the trick  -
http://www.practicalmaker.com/products/arduino-shields/ec-shield-assembled

I am currently building something similar so please let me know how you get on. What type of setup are you using ?

[Reply #4 on:]

Try these sensors

http://webpages.charter.net/tdsmeter/

[Reply #5 on:]

This is a good price for lab grade stuff
http://www.ebay.com/itm/Conductivity-Circuit-Sensor-for-Arduino-/200779531430?pt=LH_DefaultDomain_0&hash=item2ebf6484a6

[Reply #6 on:]

Hi,

Does anyone know of a module that will detect the amount of nutrients in a water solution? This is for my hydroponics setup at home. I want it to be fully automated to introduce more fertilizer in the system when nutrients are depleted.

Thanks!!!

Somebody else growing "plants" at home...?

[Reply #7 on:]

If you want a bench mark lab quality unit take a look at the hanna hi98143, which has a 4-wire conductivity circuit, pH circuit and a temperature thermi and outputs 0-4 V.

don't have a url, but this is the unit I use for calibration of my other less expensive solutions....

[Reply #8 on:]

I could use one for My greenhouse... Too. How Much do they cost? My Greenhouse is in my garage about 30 meters from my apartment but radio is no problem and it will report all that happens there...

Bob

[Reply #9 on:]

I seem to remember dropping like $600 for the unit with inline probes expensive I know, but then....

[Reply #10 on:]

Just before I retired I was involved in a redesign of a direct soil probe type of EC meter and I think I'll re work the heart of it for my Arduino, It shouldn't be that hard and even PH can be done accurately and inexpensively with other sensors. We, when I left were developing a PH meter with one of those fet sensors, it 4 years the technology should be more advanced and at $600.00 for a device albeit of lab grade is much too rich for my tastes.

Bob

[Reply #11 on:]

I have been in this sort of scientific analysis for many years, so I recommend looking at Atlas scientific website.  The complications in this area will really mess with your mind, so fork out the cash if you want a system that will work correctly.

[Reply #12 on:]

If your feed / fertilizer is an all in one job ie your not adding specific nutrients, then maybe you could use a ph sensor or measure the resistance or capacitance of the water between two probes, as many liquid plant fertilizers are oxide based and should alter the resistance, the same applies to minerals and salts. Depends how much money you have I suppose.