Sterazine is not guaranteed safe with clown loaches. Check the ingredients...it has formaldehyde in it....
Fluke meds that is safe for clown loaches and you can buy from the UK is FlukeSolve(praziquantel based med)
https://www.vetark.co.uk/pages/Fluke-Solve-for-flukes-or-tapeworm.aspx
Alternatively/additionally, I highly recommend Kusuri Wormer plus(flubendazole based med) which works against a range of worms, flukes, and also parasites like hex.
Both are safe with clown loaches.
In fact, I would buy both and treat first with the Kusiri wormer plus, 2 treatments 4 days apart. Then treat with Flukesolve. The reason being is that Kusuri is more broad spectrum and in fact also treats flukes although I buy it mainly for internal worms and parasites. If it doesn't knock the flukes(if that's what the clowns have), it will certainly knock out worms and parasites. If needed, then follow with flukesolve.
The second reason I suggest this order of events is because one should not treat with any other meds after flukesolve for about 3 weeks. The treatment of flukesolve itself can/should be run for 2-3 weeks to kill all live flukes and eggs, depending on the type of flukes.
Kusiri on another hand is biodegradable and lasts only about 4 days, hence the repeat treatment suggested 4 days apart. It doesn't not require removal after treatment so one can follow up with another med, if needed.
On a side note, flashing clown loaches could be due to water quality issues...Same applies to damaged fins....
Good luck.
