As Tom has mentioned it could be bacterial. OR you could have a different strain/type of internal parasites/worms that the particular medication your using isnt effective on. BUT.. I know this particular medication has Metronidazole, Praziquantel, Diflubenzuron. All three are great at treating for internal parasites.
Just to make sure of the basics and simple stuff... Not saying you dont know what your doing but even the most experinced Aquarist can make mistakes
You dont have any carbon or chemical media in the tank or filters? If so then remove all of it as it sucks up the meds.
How many gallons is the tank he currently is in?
How many medication tabs did you use per each dose?
How much Epsom salts are you dosing per 10 gallons of water in the tank? Should be 1 table spoon per 10 gallons.
It may take more dosages. Some cases according to the directions can take up to 3 doasages for things such as anchor worms. They also recommend for tank volumes over 40 gallons to pre dissolve the tablets for optimum effectiveness.
Directions: Remove carbon from filter during use. Add one tablet to each 10 gallons of aquarium water. Note: for tank volumes of 40 gallons or larger, and for soft and/or acid water with low alkalinity, dissolve tablets before adding to tank. Treatment may be repeated up to two times with 48 hours between treatments and a 25% water change. For anchor worms and fish lice, repeat treatment up to three times, using once a week with a 25% water change
Just to make sure of the basics and simple stuff... Not saying you dont know what your doing but even the most experinced Aquarist can make mistakes
You dont have any carbon or chemical media in the tank or filters? If so then remove all of it as it sucks up the meds.
How many gallons is the tank he currently is in?
How many medication tabs did you use per each dose?
How much Epsom salts are you dosing per 10 gallons of water in the tank? Should be 1 table spoon per 10 gallons.
It may take more dosages. Some cases according to the directions can take up to 3 doasages for things such as anchor worms. They also recommend for tank volumes over 40 gallons to pre dissolve the tablets for optimum effectiveness.
Directions: Remove carbon from filter during use. Add one tablet to each 10 gallons of aquarium water. Note: for tank volumes of 40 gallons or larger, and for soft and/or acid water with low alkalinity, dissolve tablets before adding to tank. Treatment may be repeated up to two times with 48 hours between treatments and a 25% water change. For anchor worms and fish lice, repeat treatment up to three times, using once a week with a 25% water change