Filter upgrade question.

So I totally forgot that I cannot run 2 filters. Our aquarium is on a cabinet with a shelf above it so that there is only about 1/4 of space. We designed the top left shelf to lift up so that we could change filter media, but the right shelf is perm mounted and would not allow us to reach the filter. So.....would the Aquaclear 50 be sufficient for my 29g or should I look into the 70? Thanks again for all the help!
 
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