not sure where to post this but I have added sand to my O's tank about a week ago. Love the look and I think they like it too. Anyway, sand def. shows more poo than gravel. What's the best way to clean it? Can I use my gravel vac with unwashed/unworn pantyhose ? Is there an easier or better way? Also, I just have to mention this: I basically started out with a bare bottom--only a handful of gravel--as I started setting up tank I changed my mind about what substrate I would use-- I have noticed that the past few days that the gravel that laid under the sand is now sitting on top of it and the sand has more "hills" ! Did my O's find a game to play ?

I know that my Eheim gravelvac malfunctions due to sand getting into the rotor.
I suppose the DIY bottle with the bottom cut off attached to a hose does a better job.
Every time I finish cleaning up, my small gravel is on top, after a few days all big gravel is moved back to the top!
My fish keep themselves busy with the gravel, and usually start rearanging during the cleaning!

I use my fishing net to collect the poo from the sand, I do a quick scoop & all the sand falls right through leaving the poo in the net. I probably do this once a day, i dont mind the extra work because at least I know most of the waste is out the tank so less ammonia!

lol well sand is difficult to clean sort of as long as you use good control with the gravel vac but suggestion is if you actually just hover over the sand it can get some of it but the poo too if its buried the trick i use with my python is ill go in like a reg gravle but then turn it off so the sand falls down and kinda fether the control to get the bad stuff and not a lot of sand. but the gravel comming up is prob the o's redeco the tank i have a huge pit caused by them in mine with my gravel but the sand will do that one suggestion is the panty hose will clog up if you go at it the same as you do with reg gravel. so try feathering the amount of flow you have with some trial and error.

I have gravel with my oscars but i had sand when i kept discus. To clean it hover the gravel vac over the sand to get the fish poo. If you get it wrong you will suck the sand out so put the outlet of you gravel vac into a bucket to catch the sand. The bucket can be outside and can overflow. Dont forget to lift up any wood or rocks and lots of fish poo will collect under these

Your oscar has probably been redecorating his tank by the sound of the 'hills' thing