"kim gross" wrote in
message lt.com...

For a FO tank they work very well, for a reef tank, they are not
good, because they work very well. The wet/dry filter is a great
filter for part of the nitrogen cycle, it handles the ammonia to
nitrite to nitrate very well, but it quits right there. In a FO
tank, the nitrate is not to bad most fish can handle pretty hight
levels of nitrate. But in a reef tank, nitrate is algae food, and
is an irratent to many invertabrates. So you want a low nitrate
level, if you use a live sand bed and live rock the system will not
only convert the ammonia to nitrite to nitrate, but it will also in
the areas of low oxygen in the rocks and lower sand bed levels
convert the nitrate into nitrogen gass, so you have much lower
nitrate level in the aquarium, and less algea growth.



Fabulous explanation. I've seen them work well in reef systems, but
they *can* indeed cause higher than desired nitrate levels.