Option 1 would be just fine to get a basic id of most pests in our tanks.
This was my first microscope. Still have it. Just took this picture recently.
My second microscope was a basic tungsten one up to 800x. So slightly better. I used it up until it finally broke and I got that one linked above.
You kinda went #1, #3, #5 then, eh?
And #5 has a NICE camera, as well as mechanical stage and iris light conntrol as "add ons" right?