Planting in crushed coral.

[RetroFeesh]

So, I'm setting up a shrimp breeding/grow out tank in a 20G Long and doing no substrate, but planting a few plants in plastic containers. I need to add some crushed coral since my water has no buffer out of the tap. Would there be any issue with killing two birds with one stone and placing the crushed coral in the tubs and plant into it?

[CJs Aquatics]

I have thought about this myself. I think it can be done if still dosed properly nutrient wise, the coral as a medium should have no issue allowing roots to grow depending on its particular size. I feel the issue would be adequate plant nutrition which the coral probably does not solely provide.

[Seattle_Aquarist]

On 4/27/2023 at 5:03 PM, RetroFeesh said:

So, I'm setting up a shrimp breeding/grow out tank in a 20G Long and doing no substrate, but planting a few plants in plastic containers. I need to add some crushed coral since my water has no buffer out of the tap. Would there be any issue with killing two birds with one stone and placing the crushed coral in the tubs and plant into it?

Hi @RetroFeesh

Absolutely not!  Crushed coral is calcium carbonate which is a strong base which at equilibrium can reach a pH of about 11 to pH of 13.4.  Not only can very few fish survive at this pH neither can many plants.  In addition most nutrients, including two of the three macro-nutrients, become minimally to totally unavailable to plants at a pH that high.  Hope this helps! -Roy

[RetroFeesh]

On 4/28/2023 at 8:24 PM, Seattle_Aquarist said:

Hi @RetroFeesh

Absolutely not!  Crushed coral is calcium carbonate which is a strong base which at equilibrium can reach a pH of about 11 to pH of 13.4.  Not only can very few fish survive at this pH neither can many plants.  In addition most nutrients, including two of the three macro-nutrients, become minimally to totally unavailable to plants at a pH that high.  Hope this helps! -Roy

So, the crushed coral will reach pH's that high in the container? 

[Seattle_Aquarist]

On 4/28/2023 at 5:58 PM, RetroFeesh said:

So, the crushed coral will reach pH's that high in the container? 

Yes, that is the equilibrium pH of calcium carbonate (shells, coral, limestone, etc.) in water. -Roy