DIY (very) small sulfur denitrator?

[Aleph]

Hi guys I have a 25g tank and I am struggling with a high nitrates/low phosphates issue, I started looking into making a sulfur denitrator for my tank but the problem is I have almost no free space in my sump so I wanted to ask, would it be possible in your experience to make a denitrator with a very small footprint, maybe using only one pump instead of a recirculating design? Has anyone done something similar?

Thank you!

 

[lapin]

Prob best to do more water changes