inside a deep aragonite bed?

[Backreefing]

I was thinking about the inside of a calcium reactor, and inside a deep bed of aragonite may be similar. Because the calcium reactor uses co2 to lower ph and dissolve the crushed coral. And in a deep crushed coral bed it is a no oxygen area so they may be similar. ?
im certain that crushed coral ( aragonite ) dissolves with time . This has happened to me, my aquarium. It started years ago with 3+ inches all along the bottom. Lately it was 1.25”-1.5” . It has been sucked during cleaning so it ain’t compacted . Also I noticed that this aquarium has super stable alkalinity @ 9 , and always has high calcium numbers @450+ .
Could the aragonite bed be acting as a calcium reactor and stables alkalinity ? Through bacteria oxygen becomes depleted and nitrates turns into nitrogen. This has to lower ph in the bed - calcium reactor. I’m just kicking this around . Any input from reefers that know?

 

[Flippers4pups]

Yes aragonite beds can support alkalinity and calcium.

 

[Reefahholic]

They can buffer the tank a little bit, but only if you have a very low demand. This would never work in @Flippers4pups tank. His corals would need additional supplementation.

 

[Dennis Cartier]

You can see this exact idea put into action in the DyMiCo filters. They use their gravel bed for both biological filtration and calcium supplementation. They do this by controlling the PH of the gravel bed by adding CO2 to the circulation circuit. However, their gavel beds are very, very large, far bigger than most calcium reactor media beds, so they can run them at a higher PH and still get a large amount of supplementation for the system.

Dennis

 

[Mortie31]

You can see this exact idea put into action in the DyMiCo filters. They use their gravel bed for both biological filtration and calcium supplementation. They do this by controlling the PH of the gravel bed by adding CO2 to the circulation circuit. However, their gavel beds are very, very large, far bigger than most calcium reactor media beds, so they can run them at a higher PH and still get a large amount of supplementation for the system.

Dennis

Spot on explanation, sand dissolves at a Ph of 6.8ish depending on the exact sand, i also believe the ph of anoxic zones can drop as well..

 

[Randy Holmes-Farley Verified Community Expert]

I was thinking about the inside of a calcium reactor, and inside a deep bed of aragonite may be similar. Because the calcium reactor uses co2 to lower ph and dissolve the crushed coral. And in a deep crushed coral bed it is a no oxygen area so they may be similar. ?
im certain that crushed coral ( aragonite ) dissolves with time . This has happened to me, my aquarium. It started years ago with 3+ inches all along the bottom. Lately it was 1.25”-1.5” . It has been sucked during cleaning so it ain’t compacted . Also I noticed that this aquarium has super stable alkalinity @ 9 , and always has high calcium numbers @450+ .
Could the aragonite bed be acting as a calcium reactor and stables alkalinity ? Through bacteria oxygen becomes depleted and nitrates turns into nitrogen. This has to lower ph in the bed - calcium reactor. I’m just kicking this around . Any input from reefers that know?

Sand beds do very slowly dissolve if there is degrading organic matter in them lowering pH. Some folks with long term tanks have to periodically add it. But the effect is not enough top satisfy the demand of ordinary reef tanks, and may, in fact, be more than offset in some cases by precipitation in other parts of the sand.

Note: it has nothing to do with oxygen. Only the pH matters. It lowers when organic carbon is turned into carbon dioxide.