Brown rust flatworms in drain lines

[Tigershark22]

I believe there to be an accumulation of flatworms in my main drain line and I’m looking for suggested courses of action.

I posted a thread a while ago questioning my split return lines having different flow.
I had found a pretty large brown rust flatworm in my sump filter a few weeks prior and questioned the possibility of them being in the return.

Someone mentioned that thought to be unlikely, though they’d seen it be somewhat common for them to house themselves in the drain lines to the point of clogging those.

I now suspect that may be happening. My secondary drain is now constantly gurgling. Turned the pump down only to solve the problem for a couple days. I turned off the pump for an extended period and saw another large brown rust flatworm making its way into the sump filter.

Best advice to remove without shocking the system if there is a large number of them?

 

[Subsea]

Red Planaria are a headache. In my 75G display with 30G mud/algae filter after 20 years set up they were everywhere in refugium. So, I drained & removed sump tank and rerouted sump drain thru the pump and operated as a closed loop. This proved to be a problem, because these flat worms were not treated and infestation returned.

I suggest you treat tank with flatworm exit according to directions. Because I had treated previously, I tripled the dosage rate.