The one more common thing to remember about flatworms, is they will build to a certain population density and then crash on their own. This does not always happen but "can happen". Manual removal via syphoning and having extreme water movement throughout the tank will also help eliminate them. Since the tank is relatively new, you still have allot of latitude on what you can do.
One thing you may wish to look into is Saliferts flatworm exit
. It does work but can be nastey stuff when used on a stocked tank. Since yours is primarily LR
, sand and macro's, now would be the time to consider it if at all. If you do opt for this, ensure you have plenty of carbon and prepared SW
to clean it out afterwards. Flatworm exit works best at double the dose (unstocked tanks only
) but will discolor the water greatly. Be sure to syphon out all the dead ones you can find. The smell will go away with the many, many carbon changes.
Until (if) the bristleworms get quite large, they will not be a concern. There have been reports of ones well over 12" that have been found and rarely a casualty as far as corals or fish. The wee ones you find now are years away from a problem if ever. I will often find ones in my Â¾ gal
nano 2-3" in length.