I purchased 22lbs of Ohko Stone from Aqua Forrest.
This purchase was a mix of economic and stylistic reasoning. I would have preferred manten stone, but the cost to fulfill my needs would have been significantly higher. Ohko Stone seemed be the best choice.
22lbs of Ohko Stone can easily cover 12x30 inches of ground (my needs). I was shocked by how generous and large the pieces are. This I am very happy about. I was worried I would have too little pieces to work with. I can easily make choices and edit unnecessary pieces out.
This stone is very fragile. Although Aqua Forrest individually wrapped every piece of stone carefully, one of them arrived fragmented. This stone was formally the largest and probably would have been my favorite otherwise.
The stone is basically hardened clay. Tons of soft clay is found in the holes. I live in an apt in NYC. I dont have access to a high power hose or driveway to make a mess -- so making a mess in my sink and tub is quite a bit more painful and laborious. I'm still in the process of cleaning as I write this. It would seem as though it matters not how much I brush and rinse, more clay is still finding its way out. I can easily foresee a few hours of dedication. Be warned.
If anyone has experience cleaning this stone and you have some tips. I would love to hear !! I soaked the stone over night and now I'm manually scrubbing with a narrow hard bristle brush. I think I need a new tool.
A long wooden bamboo skewer worked really well on mine. Just fill a bucket with water, soak the stone for an hour or two and start poking. I've had stones that looked completely solid and have 5-6 holes that go all the way through the stone. I'm surprised that the stone is sold as Ohko stone (ADA's name) and it's not ready for the tank. I was able to find some outside of an ADA dealer so I expected to have to pre wash it. Good luck, it's a great addition to any planted tank.