That is my point ChemiPure contains a lot of Carbon and more then likely why your system s the way it is. Believe it not a Skimmer works more like Filter then anything, all the micro particles from waste and Algae spores will stick to the bubbles and removed into the cup and all the brown sludge you on skimmer cups and in necks of the cup is fish poop and food and whatever else. It does not directly remove unwanted nutrients, it will help remove particles that will break down and become Phosphate and Nitrate. You have still a brand new system and what you have now is just part of one of stages. If your Chaeto is not dong well it's the lighting or low nutrients. If it was me I would leave it the way you have and reduce the amount a water changed to like 1 or 2 scoops of say a size of large Yogurt of Cottage Cheese Container, let that Chaeto get healthy again and then it will help you with Nutrients. Green slime and Hair Algae will always win it just reacts faster. What is your temp?

