I am using an on-chip SAR adc where for some reason I can only get accurate signal reconstruction and filtering when I sample at almost 100 times my desired sampling frequency. Specifically, the minimum working sampling rate right now is 25KHz but the desired sampling rate is 500Hz for a signal with a BW of 0.5-100Hz, therefore I am still slightly oversampling this signal but the 25KHz is clearly overkill. 

I want to downsample this signal to that desired sampling frequency to aid in the design and implementation of digital filters in that passband of .5-100Hz. I know a key thing to look out for is aliasing and because of that you should use a digital anti-aliasing filter but is it pretty much the same concept as an analog anti-aliasing filter where I simply lowpass filter the signal bandwidth that I want to reconstruct after sampling? Also are there any other pitfalls/design tips that I should know to be able to implement downsampling in a DSP? Thanks in advance.