Looking with a flashlight at night I'm noticing I have quite a few copepods on my glass but I don't see them active on my sand bed like I did a few weeks ago. I vacuumed the top layer of sand last water change. When changing my filter floss I noticed what looked to be a couple of bigger amphipods. Is it time to add another bottle of copepods or will the smaller amount I have a experience a population uptick?