Fish Situation

Thank you for replying! If you let me, I have another question about the dosage and water changes of this treatment. 

My pond has 2900 gallons and here in Spain we don't have much water to do as much water changes. 
The medication product that I have is called “Tap Pond Professional Formalachite” which has a different dosage as the one you told me. (I inserted below two pictures; one about the product and the other from the dosage of it). 
What do you think It's the best for my case about this dosage treatment and water changes using this brand of medication in particular?
There's nothing on the Internet with an actual description of what's actually in that.
I wonder if you have a picture of the back of the bottle with the ingredients.
I would:
Do exactly as the label says and repeat in a week. Maybe they engineered it right. Maybe they put copper in it. :'(
Otherwise, if the problem still exists after a few days or at the end of that week, I'd dose every other day for three rounds.
See, there are certain life stages of certain parasites that are impervious to Formalin and Malachite.
For example eggs of Trematodes, and the encysted phase of Ich.
And for both, in warmer water, the life cycle is far shorter than a week.
But you have to give the manufacturer credit for their product testing so maybe it'll work by label instructions?
And if not, we can default to the every other day, safe but more aggressive way.
IMPORTANT:  If they put COPPER in that product, it would explain why you only add it once a week.
And it's blue like a chelated copper product.