Yes, I use the Vitachem for vitamins and this is the selcon you want. I'm not sure what the powder is lolWith refrence to this I found selcon on Amazon and it referred me to this almost multi vitamin that looks like a powder you mix in water and dose. Did you use this or another product for vitamins??
Boyd Enterprises ABE16707 Marine Vitachem for Aquarium, 4-Ounce https://a.co/d/98R3I4S