I'm putting together an AP system and decided to go with Sunleaves rocks expanded shale instead of Hydroton since the Hydroton is getting scarce, plus the expanded shale is a lot cheaper, and is inert and seems to have good qualities for growing.
There is one dealer in my area that carries Sunleaves products-- the only one within 100 miles. I settled on the 0.25-0.5" size to try, because that is the closest to the diameter of hydroton, which is 8mm-16mm (roughly 0.3-0.6").
It took a couple months of bugging the guy, but he finally ordered it. I confirmed the order with him and he repeated it back-- 0.25-0.5". I go to pick it up today, and guess what he actually ordered? Right-- the 0.5-1.5". Of course-- because that's what I said-- not.
So now my question is, will this larger size work ok for growing garden veggies like tomatoes, cucumbers, beans, broccoli, etc., or is this simply too large? It normally goes for $22 per 50 liter bag, and he is willing to give them to me at $10/bag since it was his mistake.
I'm tempted to take the offer, but I'm not sure how well this larger size will work out. I would think the smaller rocks will be easier to manipulate, and will also have more total surface are for beneficial microbes.
I would appreciate any input anyone has-- even if you haven't used Sunleaves, perhaps someone knowledgeable can comment on the size of the rocks and how this might affect plant growth in an AP system.
Bill - The diameter of the rocks you ordered should work no problem. The Sunleaves shale is pH neutral and the rocks offer a lot of surface area for bacteria to grow. I've personally used these rocks in my hydroponics systems and they have worked fabulously. Let me know if you have any further questions.
I generally prefer bigger sized media as I don't have to worry about the smaller stuff being sucked into my water pumps and breaking the impellers. I have used both sizes and I see no difference in performance.