Backyard Aquaponics
A place to discuss aquaponics

Looking for ideas and suggestions to break-up larger chunks of volcanic lava rocks. I want to try using this for the medium, and the bag I got has a lot of larger, than what I want to use, chunks. Have read a couple ideas, but I am looking for a good, fast, easy method. ----- What size of chunks work OK for you ? ?

You can put the larger chunks at the bottom and smaller ones at the top. That would save you some hard work.

The size of LECA is from pea to hazelnut. Some brands are really uniform in size but some not.

What sort of lava rock you have? We have scoria in Australia. It has lots of holes and provides greater surface area for the bacteria to grow.

Good Luck

It is bagged by vigoro, and for decoration. Other than that, it just says red lava. Bought it at Home depot in the states.

If you try and break it up you will lose a lot in fine dust ect

If you are building a bigger system do as suggested put the bigger lumps on the bottom.

Find suitable size mesh screens to help you sort into sizes

I've been using those exact lava rocks for a few years now. The ones I used for my medium, I broke up with a hammer. I use small net pots though, if you're using a grow bed, you might be better off just leaving them.

I can tell you though, those rocks work great. I use them as part of my bio filter, instead of bio balls.
Right now they are in my small aquaponics system but I also use them in teaponics.

Another thing you might want to look into, 10x cheaper medium than lava, is rubber mulch.
Purchased large bags of it from home depot, dirt cheap. Also used it with aqua and teaponics last year, no issues that I noticed.
The only con is they are light compared to lava. Probably good for a raised grow bed though, it'l keep the weight down.

We used red lava rock from the big hardware stores at first. The only positive thing I can say about it is it gave us time to save up the money to buy more Viagro clay pellets. I had a leak from a faulty implementation of fiberglass in my grow-beds and had to remove the lava rock which was very difficult to dig in.
I also busted up those big pieces with a sledge hammer and OMG the amount of red silt it made astonished me. I thought I took most of it out haha not even close. I had to drain my beautifully painted 2600 gallon fish pond and clean the red off the walls and floor, although in hindsight, I didn't need to do that as fish poo and algae soon replaced the red silt I could have saved a lot of water, but dang my paint
So the bottom line is you need to clean the lava rock no matter whether you break it up or not. If you do break it up get ready to see a larger portion of that lava rock get washed out into the yard.
Brian

Thanks for some great thoughts and ideas. Rubber mulch, i like. Idea never hit me. I think I will get some and mix it with the lava. Thinking I can use those larger rocks and have the rubber fill in some of the gaps. Question: Are the various colors of rubber from some color they add after the grinding or shredding process, or is it from the solid rubber prior, when it is in large pieces. I am wondering if it is an additive afterwards, whether it might be some material that could come off and cause problems. I don't want fine paint/dye or ??? floating around.