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Unit Calculator


Unless you’re an engineer, remembering all the mathematical conversions between various units of measure is just impossible. It can be very frustrating trying to figure out how to convert a measurement into a useful unit that you can use. Even familiar measurements like cups to gallons can be confusing if you’re not using them every day. Many of us aren't familiar with the metric system.

Most people, once they’ve become familiar with the units of measure, think metric is easier to use. Just about every machine, ranging from lawn mowers to U, use metric fasteners. Even so, most Americans still like fluid ounces cups, quarts, inches, pounds and gallons.

The reef-keeping aspect of the saltwater hobby is a bit more technical. Many of the units of measure used by marine scientists and advanced aquarists are unfamiliar to us, because we don’t encounter them in our daily lives. Since the reef hobby is international in scope, many online publications and technical websites use the metric system. Most of the reef products manufactured outside of the U.S. use the metric system for dosing. You may be used to dosing by the gallon but in other countries tank size is based on liters. Old-school aquarists still remember dosing water treatments by the "capful" per gallon or even by fluid ounces or drops. This dosing language is fading away and being replaced by the metric system.

You'll even find mixed units of measure on some product labels. It's common to see a treatment label with instructions like "Add 5 ml to every 50 gallons." Do you know how many liters are in a gallon or ten gallons? How about the volume (liters) of a filter sump?

If you've taken a look at DIY treatments for calcium, the formulas can be in teaspoons, cups, grams, pounds or even kilograms. Using the wrong conversion between US or metric units of measure can be disastrous. Even errors converting from US to US units are common. When dealing with sensitive marine fish, SPS and LPS corals, proper dosing is essential for water quality stability. Accurate dosing of medications for fish quarantine tanks is critical. Miscalculations can result in ineffective low doses or harmful over-dosing of medications like antibiotics, formalin and copper sulfate. Overdosing, under-dosing and miscalculations are also costly in that they cause you to waste time and money. But all that has come to an end.

The Marine Depot unit calculator is an easy to use tool that calculates and converts common aquarium-related measurements like water flow, temperature, weight and volume into US and metric units of measure. Just select the unit of measure you have, the numerical amount and the unit you want to convert to. The calculator does the rest. You’ll be able to convert the following types of measurements.

  • Length
  • Weight
  • Liquid volume
  • Water flow
  • Temperature

The calculator converts between US and metric units. It can even figure out conversions like cups to gallons and pounds to ounces. The converter is only as accurate as the number you put into it. Double check your data before entering it into the calculator.