Backyard Aquaponics
A place to discuss aquaponics

Which is a better media..... lavarock or peagravel?

Well...

I think most people will vote for the Lava Rock. Its weighs less and has better surface area for bacterial growth. But the cons are; they are lighter and sometimes have a hard time supporting larger plants. Also it can hurt your hands when digging unless you always wear gloves.

As for pea gravel, its rounder which will make it denser and better with larger crops like corn. Also has less surface area for the Bacteria. But with all gravels its recommended that you should test the material before you put it into your AP. Some gravel contains lime which has a negative effect. Just take some rocks and add vinegar to see if it reacts with the stone. If it doesn't your good.

But at the end of the day, if you have good non lime gravel... what ever is cheap .

Agree with CJ. Another option, use lava rock(scoria) for the bottom 8-9" and then gravel or hydroton for the top 3". Saves you some $, and like CJ said, planting in lava is tough.

Pea gravel (#78) or #57 river rock all the way!

The lava I tried in some small beds had an excessive amount of fines and needed extreme washing in my opinion. The river rock you can generally hose down the top of the pile, let the fines move downward, turn the top inches a few times with a shovel if you so choose, rinse again, use a few inches and repeat.

J.B.

Your hands get used to the scoria. The fines are easy enough to wash out. I have trees in mine with no problems, they stand just fine.

Another advantage of the hydroton is it's much easier to germinate seeds in. In my system, I have tried all the types mentioned, and while growth was very similar, some differences were noted. The lava was much harder to plant in, and not very effective in seed germination. Gravel was better for planting, and germination, but from what I understand, the BSA is much less then the other 2. I really think that budget notwithstanding, the hydroton would be best. But since the best I can find is $35.00 a bag, I will use the volcanic rock, washed well, and then add the hydroton to the top 1/3...best of both worlds. Great BSA, easy planting, and easy seed germination.