r/aquaponics • u/kramfive • 1d ago

Fill for deep bed

I have some macrobins that are almost 24” deep that I plan to use for beds. What could I use in the bottom to take up space? I only want 12” of clay balls.

I have an unlimited supply of decomposed granite. Would that work?

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u/Hesh138 1d ago

Lava rock is cheap. Maybe a layer of mesh between the rock and LECA would work.

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u/snootnoots 1d ago

I used red scoria. Decomposed granite looks like it would be too fine?

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u/[deleted] 1d ago

[deleted]

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u/HistorianAlert9986 1d ago

Yeah, carbonates from the cement will always keep the pH too high for plants.

0

u/Janet_DWillett 1d ago

Skip the decomposed granite. It'll leach minerals and compact over time, both bad for your system. Go inert: capped PVC pipes, plastic bottles, or net pots for fill. Keeps weight down and water flowing.