I think the brand doesn’t matter much. They all work fine.

I will make a post about it, so it is easier accessible for others too.

TL;DR what I’ll say:

• Expensive isn’t much better
• There’s “red” LECA (smoother surface, but more compact) and “grey” LECA (very lightweight, porous and floats). Both have their own (small) pros and cons, but still similar. I just mixed them by now for aesthetic purposes lol
• The size variation matters a lot. Bigger, rounder balls = more air gaps.
• You have to soak it first in pure water when dry. If you use tap water instead, it will leach over the next weeks and alter the water chemistry, including pH.
  You can reverse this by cooking pretty fast tho