The fish get a varied diet, so difficult to say what impact can only have these tablets. I feed the Pleco Tablets but a few months on a regular basis and the fish develop still gorgeous, so I'll grab at any time again to these tablets. Compared to some other I've tried to sink the Pleco's faster and are pressed tightly. I see this in my fish but now no advantage or disadvantage.
Since you do not quite recognize the composition on the product photo I write it again here:
Milk and dairy products, fish and fish by-products, cereals, yeasts, vegetable protein extracts, algae (Spirulina maxima 5%), molluscs and crustaceans, oils and fats, sugar, minerals.
Analytical constituents:
Crude protein 40%, fat Rohöle- and 5%, 2% crude fiber, moisture content 9%
Additives: Vitamins, pro-vitamins and chemically defined substances having similar effect: Vitamin A 30400 IU / kg, vitamin D3 1390 IU / kg. Compounds of trace elements: E5 Manganese 57 mg / kg, E6 Zinc 34 mg / kg, E1 iron 22 mg / kg, E3 Cobalt 0.4 mg / kg. Dyes, anti-oxidants.
Among the ingredients, I can not say anything because I'm not an expert in the field. But as I said, the fish can tolerate it very well, so that nothing really questionable well contained.