Reddit reviews The Apex Researcher Microscope

You should be able to make out a few organelles in rotifers, you can see the mastax and mouth parts quite clearly at 400x (Do you have 10x lenses for the eyepiece?). You should be able to change the objectives and use a 100x if you really want high magnification, make sure you use immersion oil. With the 25x and 40x you are currently I don't know if you can use immersion oil to make it better with that setup (worth trying if you have some?) I can't say I know much about that particular scope though, so it may just be the low quality objectives that is giving you issues. You won't need thousands to get a good quality scope though, I bought mine for £300 and it works fantastically. You can get similar quality scopes to that one for about £200 I would guess.

Something like the one below is probably going to be the best a light microscope can do for you.

https://www.amazon.co.uk/gp/aw/d/B001EN6G8M/ref=mp_s_a_1_8?ie=UTF8&qid=1485685229&sr=8-8&pi=AC_SX236_SY340_FMwebp_QL65&keywords=microscope&dpPl=1&dpID=41DqPWmHsuL&ref=plSrch

The thing to bear in mind with light microscopes in general is that there is a diffraction limit of light past a certain magnification where there is a limit of how much detail you can get. If you are looking at images for comparison make sure to add 'light microscope' to your search. Many of the super fancy images are TEM or SEM.

Sounds like a cool project! This is the one i use at home- i don't know if it's available in the US (just guessing thats where you are) but i cannot recommend it enough. They have their own site too.

This is an alternative availble in the US - i have no experience with it but it seems okay, also has a connection to your laptop to make it easier to share your results!