Backyard Aquaponics
A place to discuss aquaponics

So what is your question CybernX?

If you are asking which you should use? Then I would say the 56 granet.

But as you are in Tampa, Generally inexpensive pea gravel is a bad idea since it is usually limestone here in FL. 1/2" or 3/4" Brown river rock may be just fine though.
granet is costly.

You might be able to get 1/2" or 3/4" expanded slate or expanded shale though.

so use rhe larger size granet then. Than you

I am suprised no one has mentioned recycled rubber mulch like they use on some playgrounds. It is heavy enough to support plants and doesnt float once waterlogged. It doesnt leach chemicals. It doesnt let in sunlight. It comes in fiber(shredded) or "nugget" form so you can control drainage and water retention. It is porous for biofilter adhesion, but doesnt retain water so no root rot. And its rubber so it wont hurt roots or hands. Looks like it sells for as little as $380 per ton, maybe even less, I really didnt search too hard. Also no wasbing or dust to clog up pumps and filters. Its also an insulator so less heat transfer when cylcing beds in the cold. The problem of getting heated up in intense sun could be solved by topping with LECA. Plus its recylcled so sustainability win!

Ascinder,
I'm not so sure about the leaching of the recycled tires. My understanding is that tires leach all sorts of bad things. I would recommend doing more extensive research on that one before trusting it.

I would also be rather shocked to pay $380 per ton for media (and I would guess that price is before shipping or delivery) I've never been willing to pay for expanded clay. I'm used to paying less than $100 a ton for media at the aggregate yards.

The first source for the rubber mulch products billed it as non toxic, but after reading your concerns, I went and re-checked and did some digging and further reading. My conclusion is that there are many government, private, and non-profit studies both for and against rubber mulch products. At the end of the day, there is not enough conclusive proof that it is safe for aquaponics use due to the inconsistency of the rubber being recycled. There is not even close to enough oversight on the types and quality of rubber being processed and little to no post testing to determine an accurate amount of safety. I had really high hopes after reading articles talking about industrial microwave treating of rubber to offgas and reclaim many of the harmful compounds in rubber and leaving behind on a safe inert product, but at the end of the day who knows if that's what really happened. At least with conventional media you know it came out of the ground with little to no processing and is pretty much inert. Oh well, the search continues.....

Thinking about recycled rubber takes me back to my track running days. The rubber top coat on the track would emit fumes that made my lungs burn. When I was in jr. high our practice field was on grass. So the once a week or so on a real track did not bother my lungs so much. In high school it was on the rubber track. My lungs burned daily and that is one major reason I only ran for one year in high school. I would not want that in a recirculating fish tank!

what about the red lava rocks, i think they are cheap, anyone ever try for media?

Yup, the Aussies call it red scoria. It is what I use. The only drawback is that it is rough on your hands, even through gloves... But with time you will be scooping into it with bare hands and thinking back to the days when you had girly hands that had a hard time with such things.

do i need to rinse it well, IE will it make the water red?

Yes the water will turn red at first but it will eventually clear. Even with washing you will get some of this color change. Try to avoid the fines as much as you can when you buy it, then put the scoria into the growbed and flush it with water till it runs out clear. After this connect the growbed to the rest of the system. Just have a bucket to catch the fines as your flushing the growbed out, if you don't want them on the ground. That should be good enough and it's a lot easier than doing it in buckets.

Cheers

lucky we dont pay a water bill so i can flush til my hears content

Yep, cause with scoria there is a lot of flushing

Forgot to mention - Leave media guard in and remove standpipe when flushing - should help get what's down toward the bottom.

I just filled my wheelbarrow with water, then shoveled the lava rock in, then drained the water, then shoveled into grow bed.

That works too but you have to move the rocks twice which is low on my list of things I like to do

What do you mean? That was how I got my media from the truck to the grow bed.