Am I throwing my $ away?

Hello everyone. I am new to the hobby and was wondering... I have a C-skim 1800 and it has always ran with mostly clear bubbles and I would accumulate a little bit of dirty water in the collection chamber each day. I added my first two fish a blue hippo tang and a clown fish last week. At the LFS they told me to get an additive (Fish Solution by Ecosystem aquarium) to prevent head and lateral line erosion on my tang. I added this yesterday and I also fed my clown PEMysis shrimp. Today I noticed I had a good amount of really dirty foam on the neck of my skimmer... it wasn't blowing out of everywhere just normal looking but nice and brown thick foam. My question - Is this foam possibly the supplement I added yesterday? If so am I just flushing my $ down the toilet? Thanks

 

Most likely, yes along with the PEmysis. I turn off my skimmer while feeding and 10 minutes after, and when adding medication or supplements 24 hours.

 

Hmmm this supplement says to add it every day. I feel like I'm doing something wrong. Maybe I should supplement once a week? I just turned off my sump to feed the mysis until i get a switch board to turn things off individually.