This item is in stock in our East and West Coast warehouses
The TUNZE Osmolator 3155 is an automatic top off (ATO) system for marine and reef aquariums. The Osmolator – short for Osmotic Regulator – automatically adds freshwater to compensate for evaporation in your saltwater aquarium.
The high-tech German designed Osmolator uses a precision optical sensor to measure the water level. Water continuously evaporates from the aquarium, leaving the salts behind. This causes the salinity to increase. When you manually pour in water the salinity is suddenly decreased. This “salinity rollercoaster” stresses the fish and invertebrates by causing extreme fluctuations in osmotic pressure.
The Osmolator puts an end to this by continuously sensing the rate of evaporation (water level) and adding back the right amount of freshwater. This brings osmotic stability to the aquarium and keeps your sump and aquarium water at the right level.
The Osmolator can be used on any aquarium, even freshwater tanks. It works when installed inside the aquarium on tanks without a sump. If you have a sump the sensor must be installed there since that is where the water level changes as it evaporates.
For forty-five years the name TUNZE® has been synonymous with aquariums. Many products and components which we have developed in the course of time are now standard features of aquarium technology today. This confidence in TUNZE is no coincidence. The company has remained true to its philosophy right from the beginning, researching water biotopes all over the world to develop components which enable natural water conditions in the closed environment of an aquarium. In the implementation of know-how, effectiveness and efficiency, TUNZE® takes the lead in environmental compatibility. Their motto is: quality and reliability. These values are upheld with well thought-out and precise tool making by highly qualified experts. The brand names of TUNZE® and Turbelle® meet the expectations of the seal of quality; Made in Germany. Many of the products shown in this catalogue are protected by national and international patents.
Manufacturer`s Warranty: 2 years from date of purchase.
We ship 99% of the products we carry for free within the contiguous United States using a mix of economy methods including USPS First Class Mail, SurePost and UPS Ground. Your order will arrive in 5-7 business days.
Over 90% of our members receive their orders within 2 business using UPS Ground. Upgrade from free economy shipping to UPS Ground for only $4.99—or spend $199 and we’ll upgrade you automatically!
Expediated shipping services are available for most products if you are in a hurry. Get guaranteed delivery in 2 business days, 1 business day, or next day by 10:30 am. Costs vary by location.
Same-day shipping is available Monday-Friday for most products—place your order by 10 am PST. Pre-ordered and back-ordered items do not qualify, nor do drop-shipped, live, or frozen shipments.
Return any new and unused item within 60 days for a full refund. Having difficulty with a product? Contact us to speak with an aquarium expert. If you need a replacement, fill out this form.
A small segment of the 180+ brands we carry require that customers contact them directly if/when problems arise. You can view the full list of those brands and get their contact info here.
Marine Depot is an authorized reseller for every product we carry. That means when you buy aquarium supplies from us, your products are not only backed by our own 60-day return policy, they also carry full factory warranties, where applicable. Some items have a 1-year warranty, others have limited lifetime warranties. Warranty coverage varies from manufacturer to manufacturer, so please read the product description of the item(s) you are considering thoroughly for details or contact us if you have warranty questions.
Rack up reward points to earn discounts on future purchases! You can earn reward points by creating an account, writing reviews, referring friends, subscribing to our newsletter, buying products, and more!
You can also get bonus reward points by purchasing select items during special sales and promotions.