Thanks for the advice. Being in Australia I cannot get that for at least a month. Who knows how many fish I could lose in that time.
I found this https://www.petcircle.com.au/product/aristopet-bird-wormer-plus-syrup/dd153 which I could pick up today.
My maths says 35ml into my 130L tank should make it just under 2.7ppm of levamisole and 0.54ppm of Praziquantel I've seen other recommendations that Praziquantel can be effective for other types of worms and shouldn't hurt the inverts.
I dare say this will work but another pair of eyes looking at it would put me at ease. It hurts me when I loose 1 fish and cannot figure out what was wrong, if I poisoned my tank I'd probably quit the hobby.