Except for spironucleus / hexamita, the parasites shown on that site are external parasites found on the skin and in the gills, not in the feces. And just a quick note, when you look at spironucleus at 400x, it will look like a tiny moving little thing, not like the detailed picture you see on that site, because that one is shown at a much higher magnification.
First, look at the feces quickly at 40x to see if there's anything obvious. Then look at the feces at 100x. Start at one corner of the slide, and scan methodically from left to right, then down one row and right to left, and do this for the whole slide while adjusting the focus in and out to see what's on top and what's on the bottom. If you see anything suspicious, center it and go to 400x to identify it.
Look for:
- Egg worms. Any round shapes, usually you will find many identical round or oval shapes of similar size. Food debris can sometimes look similar. If you find something suspicious and you're unsure, you can take a video or a picture with your cell phone and show us what you find.
- Live worms. Some worms are parasitic and some worms are harmless, they just live in the aquarium and come to feed on the feces. So to be able to distinguish between the two, you need to examine feces that are as fresh as possible. Letting the feces sit on the sand even just for a few minutes is enough to contaminate a sample with harmless worms.
- Live protozoa, such as spironucleus. Again, there are harmless protozoa that look a lot like spironucleus living in your aquarium, so your sample needs to be as fresh as possible. If you can't get a fresh sample at the moment, you can still look at older feces to at least see if there are worm eggs.
Capillaria worm eggs at 400x:
Other types of nematode eggs:
Hexamita / Spironucleus:
