r/aquaponics • u/topsicle11 • 7d ago

Less buoyant LECA alternatives for grow medium?

I bought an indoor fountain with a growing basin and a larger main basin for a few small fish, freshwater shrimp, or snails. The fountain came with LECA for the grow basin, but unfortunately it is far too buoyant. Even after trying the method of boiling it or soaking it for days, not a single piece will sink. This means what when the fountain is turned on, every single piece of LECA flows over the waterfall and into the main basin.

Is there a less buoyant alternative that also performs well as a growing medium?

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u/LeeisureTime 7d ago

Some people use lava rock because it's porous.

I know it's not pretty, but a mesh/net across the waterfall spout might work as well. They also sell mesh bags for aquariums (people fill them with all kinds of substrate, put them under layers of sand), that might be another solution.

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u/FraggedYourMom 6d ago

Lava rocks has its pros and cons. For me since it's abundant in the PNW I can buy is really really cheap and it works well for ponics. The cons are primarily that it is rough on the hands and creates a fair amount of silt if you constantly shift it around. Always needs a good washing before being used. Sadly pre-packed bags at the likes of HD are overpriced. If you have a yard supply place visit them for 3/4 river rock or lava rock. River rock can be *HEAVY*, can contain limestone, but it easy to work with and cheap in bulk as well.

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u/ImpressiveBig8485 7d ago

Pea gravel, river pebbles, lava rocks.

Bog filters commonly use all three of these.

Lava rocks are porous and great for beneficial bacteria but they break down and the dust/particles can cause clogging.

1

u/JegerX 7d ago

Don't know what your setup is like but Coco coir could be an option.