Tunze Osmolator Universal 3155 ATO
TUNZE_OSMOLATOR_3155
The Tunze Osmolator Universal 3155 is an automatic top-off system that combines a non-wearing optical eye sensor with a backup float switch to maintain a stable water level and salinity....
Or build it into a bundle — save up to 6% ↓What it is, and who it is for.
The Tunze Osmolator Universal 3155 is an automatic top-off system that combines a non-wearing optical eye sensor with a backup float switch to maintain a stable water level and salinity. It ships as a complete kit with the Tunze 5000.020 metering pump (15 gph, 7.2 ft max head), magnetic sensor holders, tubing, controller, and power supply. Built-in safety features include run-dry protection, empty-reservoir alerts, and an overflow timer that shuts off the pump.
Build around the Tunze Osmolator Universal 3155 ATO.
It's already in your system below. Add the flow, filtration and dosing around it and the discount starts working — tiers climb as the build grows, and the reef meter fills with it.
Pick the right one, not the biggest one
The honest line-up from ato & ro/di. Most buyers reading this page should buy the middle column.
BRS 4-Stage 75 GPD RO/DI System
Tunze Osmolator Universal 3155 ATO
BRS 4-Stage 75 GPD RO/DI SystemAsked before checkout
The questions our support inbox actually gets.
Does it ship quickly?+
Orders placed before 2 PM ET on a business day leave the same day. Tracking is emailed the moment the label prints.
What if it's the wrong fit for my tank?+
Return it. 30 days, no restocking fee, refund to the original payment method. Better: tell us your tank first and we'll spec the system for free — half of all returns are sizing problems.
Who handles the warranty?+
We do. Everything carries the manufacturer's warranty and we run the claim for you — one email to us instead of a ticket queue.
How does the bundle discount work?+
Add items in the bundle builder: 2+ items saves 5%, 3+ saves 8%, 4+ saves 12%, and 5+ saves 15% off the whole system, applied at checkout.