Yes, the idea of the long tube is to remove the O2 along the way so there is on O2 left in the water when it hits the media, in a closed loop you would still introduce O2 to the media
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100 gal touch tank for propagation;Current Sunpod2 HQI @1400k HQI ,38 gal Korrall sump, ASM G-3 skimmer, Mag 9.5. Stock changes often 125 gal ;Aqualight Pro HQI 2 HQI@1400k / Compact Fluorescent/Lunar Light Fixture, 5 powerheads, 30 gal sump, mag 12(return),Ocean runner 3500(return through chiller), ASM G-3 skimmer, UV sterilizer, Artic chiller Tobacco bass, maroon clowns, Seriatopora guttatus, Seriatopora hystrix, capricornis, Acropora, Spongodes, porites, Turbinaria,Stylophora pistillata, etc |