Here the old controller and a circuit of a barebones meter I'll try to design a better controller around buy nulling out the 20 millivolts from the 20 pico amps of current from the 1 gigaohm probe.
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Andrew, Eheim Club Member #24
This message is always under construction: 75-gallon tank; 2, Eheim 2026 filters; Tek Light with 4, 54W T5s (6000K) ; Sand on top of 4:1 sand:clay mixture; Milwaukee CO2 controller; PlantGuild vortex CO2 reactor; pH = 6.6, kH=70mg/l, GH=120mg/l; EI; Flourish excel on 50% weekly water change: AGA Member.
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