Ahhh... finally back where hobby internet available again.I'm growing in coco, hydroponically
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I will ignore them if they give me crazy readings and use my EC pen and some Litmus paper
Over the decades involved with dozens of projects involving PH, EC, or level sensing. I agree with the difficulty choosing electrode material. Specially those first two. I agree test paper is a better solution or handheld instrument requiring proper calibration and storage in buffer solution (should be changed daily, real hassle). In any case stainless steel not used for PH anyway, commercial or DIY. Even basic level can prove problematic for reliable long term automated sensing.
Although not a partaker myself, more recently required to help w/couple COCO setups. Basically simple reservoir level but even that not as easy as it sounds. Tried several metals and, as previously experienced, stainless steel one of the worst.
Bacterial/organic buildup on the electrodes pretty much insulates after a few days or weeks causing premature alarm. Several other metals, including tinned hookup wire, went much longer. Even galvanized or plain non-stainless steel. Along with many boat owners, found cheapo copper worked best underwater. Stripped solid un-plated cat5 connected directly to couple GPIO for example. Not ground because important to measure briefly (millisecond) then turn off both the output and input-pu to minimize plating/corrosion. I'm told by both users it's worked well for multiple runs now w/o cleaning or replacement.
Let's not even mention soil which may be orders of magnitude more difficult. Specially long term.
Sometimes simplest/cheapest is best.
Statistics: Posted by emma1997 — Tue May 21, 2024 7:15 pm
