The Complete Buyers Guide To Caravan Water Monitoring Systems

Running out of water at a remote campsite is a mistake you only make once. Water monitoring systems tell you exactly how much water you have left in your fresh, grey, and black water tanks, so you can plan refills and manage consumption rather than guessing. If your caravan doesn’t have a tank monitor (or has one that doesn’t work reliably), adding one is a cheap, high-impact upgrade.

Understanding Caravan Water Capacity

Most caravans carry between 80 and 160 litres of fresh water, depending on size and configuration. A typical family uses 20 to 40 litres per day for drinking, cooking, washing dishes, and basic hygiene. This means your water supply will last 2 to 8 days before needing a refill, depending on your tank size and consumption habits.

Grey water tanks (from sinks and showers) are usually similar capacity to fresh water tanks, while black water tanks (toilet waste) are typically smaller at 40 to 80 litres. Knowing your exact levels across all three systems prevents the embarrassment of overflowing grey tanks or running out of fresh water when you’re planning to stay another few days.

What Type of Monitor Do You Need?

Tank level monitors: The essential system. Shows how much water remains in each tank as a percentage or volume. Most important for fresh water (so you don’t run dry) and grey/black water (so you don’t overflow).

Water flow meters: Track how much water you’re using in real-time. Helpful for understanding consumption patterns and teaching kids (or adults) about water conservation. The Outback Explorer Bluetooth Water Flow Meter ($60) connects to your phone and tracks daily usage.

Hot water temperature monitors: Show when your hot water system has heated up, preventing wasted gas or electricity. Usually built into comprehensive monitoring systems rather than standalone units.

Combined water and power monitors: All-in-one systems that show battery levels, solar input, and tank levels on a single display. More expensive but tidier installation. Popular options include the BM Pro Odyssey system.

Technical Types of Water Monitors

Probe-style (resistive) sensors: The most common factory-fitted option. Metal probes inside the tank measure water level at set points (typically ¼, ½, ¾, full). Cheap and simple, but notorious for inaccuracy as probes corrode, get coated with mineral deposits, or give false readings. If your factory-fitted level gauge seems unreliable, this is probably why.

Ultrasonic/non-contact sensors: Mount externally on the tank (no contact with water). Use ultrasonic pulses to measure distance to the water surface. Far more accurate and reliable than probes because nothing corrodes or fouls. Give continuous level readings rather than just ¼ increments. Around $100 to $250 per tank.

Pressure-based sensors: Measure water pressure at the bottom of the tank, which increases proportionally with water depth. Accurate and reliable. Some require a fitting to be installed in the tank; others clamp externally. Around $80 to $200 per tank.

App-based systems: Modern monitors connect via Bluetooth to your phone, giving you tank levels at a glance on an app. Convenient but dependent on phone battery and Bluetooth range.

Best Monitor Brands

BM Pro: The Australian market leader for caravan monitoring equipment. Their systems range from basic tank level indicators to comprehensive management displays that monitor everything from batteries to water to gas. Well-supported through dealer networks Australia-wide.

RV Electronics: Specialises in aftermarket caravan electronics including tank gauges and monitoring systems. Good reputation for reliable, affordable products that are easy to retrofit to existing caravans.

Topargee: Known for robust, Australian-designed caravan accessories. Their monitoring products are built to handle harsh conditions and integrate well with other Topargee systems.

Mopeka: Originally famous for gas bottle monitors, now makes excellent ultrasonic water tank sensors that integrate with Victron and other premium electrical systems.

Platypus: Offers combined monitoring solutions that track both tank levels and water filter condition, appealing to travellers who want comprehensive water system oversight.

Our Recommendations

Detailed Breakdown

BM Pro Dipper Water Tank Level Indicator ($105): Our top pick for most caravanners. A reliable probe-style sensor that’s far better quality than most factory-fitted gauges. Shows tank levels on a clear panel display. Australian-made and well-supported. Great value upgrade if your existing gauges are unreliable.

Mopeka 12V Top Down Sonar Water Tank Sensor ($199): Premium ultrasonic sensor that mounts on top of the tank with no drilling required. Connects via Bluetooth to smartphone apps and integrates with Victron systems. More expensive but eliminates probe corrosion issues completely.

RV Electronics Double Tank LCD Water Tank Gauge ($115): Monitors two tanks (typically fresh and grey water) on one LCD display. Good value if you need to track multiple tanks and prefer a dedicated display rather than phone apps.

Outback Explorer Bluetooth Water Flow Meter ($60): Tracks real-time water consumption through a smartphone app. Install inline with your water pump to monitor daily usage patterns. Excellent for understanding consumption and encouraging water conservation.

Platypus Water Tank Monitor and Filter Monitor ($249): Unique system that tracks both tank levels and water filter condition. Alerts you when filters need replacing. Perfect for travellers who want comprehensive water system monitoring in one unit.

BM Pro Odyssey Link & Control Caravan Management Display ($915): The premium all-in-one solution. Monitors water tanks, battery systems, solar panels, and more on a single touchscreen display. Expensive but eliminates multiple gauges cluttering your control panel.