There are a few potential problems with these filters. One, they can sometimes eject part or all of their media into the tank. Two, in the event of a power failure, all the sand in the filter will settle to the bottom of the tube. If power isn't restored soon, the bacteria on the sand will use all the oxygen and the lower areas will become anaerobic. Then, when the pump comes back on, all the potentially toxic waste products generated by the anaerobic area and the dead aerobic bacteria will go into the tank. Third, there are better ways to process the ammonia and nitrite in a tank. Unless you don't intend to use
LR in your tank, you really don't need any additional biological filtration. Also, if you set your tank up with a
DSB, you'll have a natural way to export the nitrates that will build up. The
LR will help to an extent with nitrate conversion, but
IMO, it's not enough for most tanks.
JMHO.