Leca size

[Adamantis]

In Sweden I can get two sizes of leca, 8-14 mm and 12-20 mm. What´s the arguments for the two size ranges?

[Murray]

Too fine and you will develop blockages and dead spots...unless you pre filter the water entering the grow beds.

[Adamantis]

The 12-20 mm looks much bigger than the canna leca you guys use. About twice the size.

[Murray]

Hi Adam,
It is the only size we can get here in Aussie. I much prefer to use 20mm gravel for the reasons stated above. Some folk who live in inner city areas just cannot get ordinary 20mm gravel, so the CANNA clay pebbles are the best option for them.
We have grow beds that have 20mm gravel that are now just short of 5 years in operation, loads of worms in them, but a couple will need a clean out very soon ...as soon as the current crops are finished.

The clay pebbles needs a clean every 18 to 24 months we have found....still very good performance.......but the 20mm gravel is much lower cost and has longer service life.

The clay pebbles are excellent for smaller systems where it is much easier to get a few bags of clay than to try haul some gravel from a quarry somewhere. Indoor systems in cold climates and the like.

[Adamantis]

So bigger is better because it doesn't clog up as easy? Leca is quite cheep in Sweden as we produce and export. 2.2 AUD for 10 l. The leca isn't quite round, so most of them are about 20 mm across and down to 12 mm tall. The 12-20 mm looks like your 20 mm gravel in size. Perhaps its perfect

Btw, does it ever stop floating?

[Murray]

The CANNA and Hydraton stop floating after a few days, maybe a week at the most.

[Adamantis]

Thanks Guru Murray!