i dont have a gravel cleaner aka syphon, what i do in between taking the majority out and rinsing it in hot water is i have a long handle spoon and i gently stir up the gravel, just enough to make whats lurking underneath come up and i dump that water in my bucket. i guess its good to keep some of that 'stuff' as its good bacteria for the fish.. i have only been at this a few months myself but about every 4-6 weeks i take so much out the other times i stir it up. also note you should have aquarium only buckets,cups, cloths, whatever you use to clean it. no bleach or soap chemicals are allowed on those items, so ive been advised.. please those who are experienced jump in and correct me if i am wrong.. oh be careful when doing this you must be gentle so you dont stress the fish, if you have small algae eaters or ghost shrimp too. i have stirred up a couple ghost shrimp i forgot as i was focused on my cleaning..