An ORP meter is only as good as its probe so a replaceable probe option is a must.

ORP - Mv meters are the most accurate way of testing for your water quality and bio load, which is very important for judging when to do water changes and to make sure nothing is starting to go wrong. The higher the reading the ORP reading the better quality your water is and visa versa. these meters are invaluable in knowing the health of your tank or pond.

The ORP water proof pen style meter is designed and made for high accurate precision measurements. Easy to use and read with its large LCD display that shows 3 point reading clearly. the meter also has a hold function so you can note your accurate reading away from the tank or pond.

Due to its replaceable probe there is no reason why this ORP meter can not last a lifetime.

Digital ORP meters are fast becoming the largest selling digital aquatic meter due to the high accuracy and ease of use.

What is ORP and REDOX?

Redox or better know of short as ORP is eminently important as an indicator not only of a system's capacity for cycling waste, but indeed of chemically supporting fish, plant, and invertebrate life. There are both oxidation (e.g. biological conversion of ammonia to nitrites to nitrates) and reduction (ridding systems of nitrate aka denitrification, bio-phosphate PO3) that must occur readily in a truly closed system to support (macro-)life.

Redox is measured indirectly as the ability of an aquatic system to conduct electricity, in millivolts (mV, 1/1000 of a volt). Hence the term Redox potential, or, if you will, ORP for, you guessed it, Oxidation-Reduction Potential. Testing can be done periodically, but ORP can change so rapidly that in order to fully benefit, most people who are so inclined, check the reading on a daily basis.

Technical parameters:

Range: 0.00~+/- 1999mV
Resolution: 1mV
Accuracy: +/- 5mV
Power supply: 4x1.5v AG13-5 batteries