Milwaukee Instruments MA911B/2 Double Junction Ph Electrode with 2 m Cable and Gel Filled Electrolyte Solution

I bought this to replace my old one that I had installed for just over 4 years. it was only after 4 years of permanent usage in my fish tank set up when it became inaccurate. Some person before me commented that if it is meant to be used in a aquarium then why is it bright yellow? Well, I guess they read the comment as well because the one I got sent is green. For me it doesn't matter as it is installed in a sump but for those who put it straight in the tank it is a nice change.

Using this in a reef tank. Cheaper than the Neptune Apex probe and works just as good. Word of warning, let it sit in the tank water for a a week before calibration. This probe ships with a KCl gel to keep the probe hydrated. Around day 5 in my tank, some of this gel that had worked its way up into the probe started to expand and offset my readings by about 0.25. Thinking it was some kind of tank goo, I just gave it a swirl. Later, I see my PH spike back to a "normal" reading. Other than that, this probe has worked well so far. It's been accurate (when not blocked) and consistent. I included a screenshot of my PH graph to show how things seemed fine for a few days, then the gel likely blocked the junction and PH was "suppressed" for a couple days before the huge spike at the end when I notice the gel/cleaned the probe.

Buona per il lavoro

Received the probe but it wasn't properly stored in its liquid quich leaked during the travel. The probe now don't give a constant reading which increase gradually in the span of a few hours until it is totally off the real PH.

Worked as a great replacement for the probe on my MW102. Easy to use, quick readings, and calibrates reliably. For some reason buying the unit with the longer cable is cheaper than the normal MW102 units.