Can you use sand with Gravel Fliter?

[Fishbreeder]

I Recently got a 30 gallon tank for free and it have a under ground filter and wondering if i can use sand with it?

 

[HUKIT]

Sand does not work well with a UGF, I'd personally advise you to ditch that thing and get a Aquaclear 70 HOB. UGF's do work very well in terms of biological filtration, they essentially turn the substrate into biomedia but when enough detritus collects under the plates the tank must be broken down to clean otherwise this will effect the build up of nitrates.