Active Filter Explanation

These filters are fully "cycled", containing all the many species of nitrifying bacteria a fully established aquarium needs. Once put into a tank, the tank becomes instantly cycled. "Cycled" does not mean you will not get ammonia or nitrite readings from a test kit. It means you have the proper number of nitrifying bacteria species and the proper proportion of them. However, the population may not be high enough to handle all the waste produced by your animals. Assuming you have enough filtration for your bio-load, the bacteria will double in population approximately every 24 hrs until it reaches the level where it can handle the waste in your tank. That can take anywhere from minutes to days, depending on the bio-load in your tank.

All of our tanks contain snails, so these filter may have small snails and/or their eggs on them. Also, they contain the decomposed waste generated by the plants and animals in our tanks. They will be "dirty". This is not harmful and is what happens in biological filters. The nitrifying bacteria are short-lived and create a large amount of bio-floc as it dies off.  All of this is normal, but if you are  offended by this, please do not order. Filters that are too clean, can be a reason for having a difficult time establishing a bio-filter since cleaning a filter too much harms the bacteria.

There are likely hundreds of species of nitrifying bacteria in a tank that has been "established" for over a year. This is why those commercial "starter" products with a dozen or so species, don't work very well.  Our filters contain all the species in balance and is why they work so much better.

The bacteria survive shipping quite well, but faster is better when deciding on the shipping method during checkout.  If the filter freezes, the bacteria may be killed so pay attention to the weather, here and where you are.  Try to avoid having the package sitting outside after delivery.  It can be risky to order when night-time temps are much below 0 F. We are in a potentially very cold area of the country (zip 14760).  Heat does not bother the bacteria.  In transit, the bacteria go into a dormant state and reactivates in the presence of ammonia and nitrites.  A percentage of them will survive for quite a long time out of an aquarium, so even with delays and bad weather, they persist and will often still work, though a bit slower as they recover.

The filters vary in size and shape within the range listed.  All of our Active filters are the "Internal Weight" filter version.  We have too many filter types to have them all in an "active" version and this type is easy to ship without water leaking from the bag.

These filters are "established" in our disease-free aquariums.  This assures that no pathogens are transferred to your fish.  This is safer than using a filter out of your own tanks, since few, if any are disease-free.  These filters have been running for about a month in our super healthy tanks to ensure the nitrifying bacteria are well established within the sponge.