That's a big filter, that should turn over the volume about 7.2 times per hour provided that the 900 GPH they boast is accurate, but like you said you are under-stocking so you should be fine.Just keep an eye on your levels and if you think you need more filtration add a larger HOB.
HUKIT said:Those levels advertised are without media, it's around 625gph.
Mogurako said:I thought 900 seemed high, it's that true with all canisters, you have to take a % of the GPH?