The Garnet 709-4 SeeLevel II is designed specifically for fifth wheel trailers and RVs with four separate holding tanks - including a dedicated galley (kitchen sink) tank. Unlike factory-installed monitors that show vague quarter-tank increments (and often show "full" when you're not), the SeeLevel II displays actual percentage levels from 0% to 100%. The secret? External sensors that mount on the outside of your tanks – where sewage buildup can't affect them.4 Tanks% ReadoutFifth Wheel
0-100% accurate readouts
No fouling, no false readings
Fresh, Grey, Galley & Black
Voltage readout included
With multiple models available, choosing the right SeeLevel II system can be confusing. Use our SeeLevel II Comparison Guide to find the perfect match for your RV's tank configuration and feature requirements.
One of the best features of the SeeLevel II system is the ability to add additional monitors at other locations in your RV. The common bus wiring allows you to connect multiple displays to the same sensor network. Popular second display locations: • Bedroom or bathroom for overnight monitoring • Outside water bay for convenient dumping • Cockpit/living area for quick checks • Near the galley for water conservation awareness Simply purchase an additional 709-4 Monitor Only and wire it to your existing sensor network – no additional sensors needed!
Many fifth wheel trailers and larger RVs feature a separate galley (kitchen) grey water tank in addition to the standard fresh, grey, and black tanks. This design keeps kitchen waste water separate from bathroom grey water, which can help with odor control and allows for different dump schedules. The 709-4 is designed specifically for this four-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 • Grey Water Tank: Plan showers accordingly • Galley Tank: Monitor kitchen sink drainage separately • Black Water Tank: Know exactly when to dump – no guessing
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.
Important: On the 709-4 system, grey and galley tank sensors cannot be stacked – they are limited to single sensors only (maximum ~14" tank height with the 710-ES3 or ~18" with the 710-SS2). Fresh and black tank sensors CAN be stacked for taller tanks. If your grey or galley tanks are taller than 18", contact Garnet support for guidance.
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. The hardest part is accessing your tanks – the actual installation is straightforward:
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.
Want to check tank levels from the bedroom, bathroom, or wet bay? Simply add a 709-4 Monitor Only to your system. Multiple displays can share the same sensors via the common bus wiring – no additional sensors required!
Fresh & black tanks can use stacked sensors. Grey & galley are single-sensor only.
→ View Complete SeeLevel II Comparison Guide
Manual: SeeLevel 709 Manual (PDF) Support: garnetinstruments.com/support Warranty: 1 Year Limited