Review on 🐠 Hagen 15-Pack Marina Slim Aquarium Water Filter featuring Zeolite Plus Ceramic Cartridge by Kimberly Elliott

We used these filters in our Marina S20 filter which uses four of these filters at once. It makes sense to buy this inexpensive multipack to always have on hand. We took turns replacing a filter every time the tank was cleaned, so weekly. Lately, however, the filters are no longer so dirty that they can be replaced. They can be washed under running water at room temperature to extend the life of the filter. (Water that is too warm kills the beneficial bacteria in the filter and can upset the balance of the aquarium.) It is advisable to replace a particular filter when the material on the filter begins to "fall off" or "roll". We highly recommend these filters as well as weekly 30-40% changes of the purified tap water. We replace 4 gallons each week with Nutrafin Cycle for two gallons and Nutrafin Aqua Plus for the other two gallons. Using these products and this process, we were able to keep four goldfish alive in a 20 gallon aquarium for about six months.