First time use - Grog rock

[Reefer1]

I posted a few months back regarding using grog rock as a column packing,
Thought i would just share my experience
so i managed to do a run yesterday ⁹with my 46" x 2"column packed with it, sized at roughly 5 - 7mm with 40" of rock and a copper mesh roll to hold up the grog rock.
Started with a 23L charge of 20 -25% abv, power settled in at 550watts throughout the run, nice and slow 20ml pm.
The run was long, 9 hours, longer than usual.
After fores and heads ran off it settled into 87 abv for the first 500 ml and subsequently abv dropped a 2 to 3 % as i swapped the 500ml jars out, the run was without problems.
A surprising thing though, i got tails at 40% abv, normally its around 20 - 10 abv, when the cloudy stuff appears, so i stopped at that point.
The yeald was 5.5 litre with 0.75 litre of cloudy tails which i will chuck in next strip i do.
Product tastes pretty good, no taint from the rock.
I added my sight glass to the column and noticed a fair bit of reflux going on, which i never saw with copper mesh, also the abv was roughly 10 to 15 % higher throughout the run.
This Grog rock isnt lava rock, its a man made ceramic product, it's very hard and smashes up pretty well with a hammer, once graded it dosnt break up in the column, its a no brainer for me, i will be using it from now on.
Big Thanks to the team for the initial advice on sizing.
Reefer1