What’s wrong with my tank?

[Jayreef23]

So for a while now my corals have been stagnant and do not grow but instead die off slowly and are overtaken by something red/ brownish color. I noticed I have flatworms…a lot of them. Could that be the cause? everything else is ok (parameters)

 

[Stephen8169301]

@vetteguy53081

 

[Sleeping Giant]

looks like cyano, flat worms aren't good either. both are treatable.

 

[vetteguy53081]

So for a while now my corals have been stagnant and do not grow but instead die off slowly and are overtaken by something red/ brownish color. I noticed I have flatworms…a lot of them. Could that be the cause? everything else is ok (parameters)

Your issue is red planaria flatworms which are some of the worse and are a great nuisance pest which populate quite quickly and can quickly smother corals and block the needed light for production of zooxanthellae which is their energy source.
Removal can be accomplished by siphoning them with a 3/8" tubing into a nylon stocking and discard
OR
Add a wrasse such as Yellow coris, 6 line, lunare or malanurus OR even a springieri damsel which will eat them
With this many, you may have to resort to Flatworm exit. Only big caution with flatworm exit is that the dead worms which have toxins have to be siphoned daily to reduce toxin risk.
With the number you have, for the next 2 weeks you will have to look for eggs and scrape off as there is likely some and would be future acoels. Eggs are really tiny