The Garnet 709-2 SeeLevel II is designed specifically for RVs with only two holding tanks – typically a fresh water tank and a black (waste) tank. This configuration is common in truck campers, pop-up campers, smaller travel trailers, and some older RVs that don't have a separate grey water tank. The 709-2 also monitors your LP gas level and battery voltage, giving you complete system awareness in a compact package.2 TanksLPG Monitor% Readout
0-100% accurate readouts
No fouling, no false readings
Uses existing propane sender
Voltage readout included
The 709-2 is ideal for RVs that have only fresh and black tanks (no grey tank): • Truck Campers: Slide-in and pop-up truck campers often have just 2 tanks • Pop-Up/Tent Trailers: Many folding campers have limited tank configurations • Small Travel Trailers: Some compact trailers combine grey/black or skip grey entirely • Older RVs: Many vintage units were built with just 2 tanks • Custom Builds: DIY conversions with simplified plumbing
If you're not sure whether your RV has 2, 3, or 4 tanks, check under your RV or consult your owner's manual. Use our SeeLevel II Comparison Guide to find the perfect match for your RV's tank configuration.
Traditional RV tank monitors use probes that extend inside the tank. These probes quickly become coated with waste residue, toilet paper, and struvite buildup – causing the dreaded "always shows full" problem that plagues nearly every RV owner.
The SeeLevel II difference: Sensors mount externally on the tank wall using 3M adhesive. They measure tank levels through the plastic tank wall using capacitive sensing technology. No probes inside the tank means:
• Battery Voltage: Know when batteries need charging • Fresh Water Tank: Know exactly how much water remains • Black Water Tank: Know exactly when to dump – no guessing • LPG/Propane Tank: Monitor propane level via existing sender
The 709-2 connects to your RV's existing propane tank sender (the sensor built into your LP tank gauge). It does NOT include a propane sensor – it uses the one already installed in your RV.
The 709-2 does NOT include a water pump switch. If you need a pump switch with 2 tanks, choose the 709-2P instead. If your RV has 3 tanks (fresh, grey, black), you need a different model: • 709: 3 tanks + LPG (no pump switch) • 709-P3: 3 tanks + pump switch (no LPG) • 709-P3W: 3 tanks + pump switch + LPG
Garnet offers three sensor sizes to match your tank heights. Sensors can be cut shorter or stacked for taller tanks:
Tip: The 710-ES3 (12") is the most popular choice and fits most standard RV tanks. Do NOT mix sensor types when stacking.
SeeLevel II sensors work on plastic/polyethylene and fiberglass tanks only. They will NOT work on metal tanks. Tank walls must be 3/8" (10mm) thick or less.
Most RV owners can install the SeeLevel II system themselves. With only 2 tanks, the 709-2 is one of the simplest SeeLevel systems to install:
Complete installation instructions included. For detailed guidance, download the SeeLevel 709 Manual (PDF). Professional installation recommended if you're uncomfortable with electrical work.
The SeeLevel II includes diagnostic capability that allows you to check the operating characteristics of each sensor. If a sensor develops a problem, the display can show you the signal level and help identify the issue.
Sensors can be stacked for taller tanks up to 34.5". Do NOT mix sensor types when stacking.
→ View Complete SeeLevel II Comparison Guide
Manual: SeeLevel 709 Manual (PDF) Support: garnetinstruments.com/support Warranty: 1 Year Limited