Help parasites on fish!

[Guppy._.lover]

Red wormqqs are being found in my guppy tank and when a fish eats the they die within a week I've heard that even though you clean your tank they still transmit through other infected fish poop any medication???

 

[nic1]

Sera nematol

https://www.amazon.co.uk/dp/B0013ZAGJQ/?tag=

 

[Essjay]

Or eSHa-ndx, which contains levamisole.