Marine pure placement

TankMaid · Jul 7, 2020

All, I am considering the placement of my marine pure blocks. Is it better to have high flow through it or low flow like the bottom of the fuge? I have attached 2 pictures for reference. Thanks in advance.

Spare time · Jul 7, 2020

High flow. These medias are only effective if you can deliver the ammonia and nitrite as well as oxygen (and more etc) to the bacteria. Just make sure they don't get clogged with gunk and heterotrophs.

The idea behind low flow denitrification would be that you have no oxygen in there because of low flow, but denitrification can either produce nitrogen, nitrite, or some form of sulfer (I forget what the exact chemical name is).

TankMaid · Jul 7, 2020

Spare time said:
High flow. These medias are only effective if you can deliver the ammonia and nitrite as well as oxygen (and more etc) to the bacteria. Just make sure they don't get clogged with gunk and heterotrophs.

The idea behind low flow denitrification would be that you have no oxygen in there because of low flow, but denitrification can either produce nitrogen, nitrite, or some form of sulfer (I forget what the exact chemical name is).

Thanks, any advice on keeping it from getting clogged?

ScottB · Jul 7, 2020

TankMaid said:
All, I am considering the placement of my marine pure blocks. Is it better to have high flow through it or low flow like the bottom of the fuge? I have attached 2 pictures for reference. Thanks in advance.

Ages ago, I explored the same question. In the end, the consensus seemed to suggest low flow if you are trying to process nitrates out. High flow if you are trying to process ammonia and nitrites.

If you are doing minimalist aquascape (less live rock) then you may be better served with high flow for processing ammonia/nitrite. If you think you have enough rock for that, then low flow will keep your nitrates down.

That consensus appears to be working for me. My tank can process nitrates very efficiently -- almost too efficiently -- with the block in low flow. I have six of the big blocks in +400G total. That is 1,536 cubic inches of block. But I am heavy food in / heavy export.