New to this excellent forum. I have a question in the treatment of gill flukes.

I have a 1200 liter tank with plants, substrate, discus & many tetras. The tank has a large sump. I currently use Kusuri (monthly), water changes at 50% per week, and gravel syphoning. Fish eat very well, water is good, poo is black, however the discus flash more than I would like.

My query regards the correct meds:
Trichlorfon label notes ‘temp must be below 27 degrees’ - improbable in Qld this time of year - rules this out!
Praziquantel label notes ‘cannot be used with tetras’ - rules this out!

How do I get around this? Will reduced doses work, when & how often, and will this work better than Kusuri? Or am I being over the top?

I have a few thousand dollars’ worth of fish and do not want to risk a catastrophe.

Any advice would be greatly appreciated.