Backyard Aquaponics
A place to discuss aquaponics

I agree.
Timmy, I used 50L of water to wash 0.5m³ and had 30L left over when I was finished.

Also, check out my photos, those fines are rock hard in the bottom of the barrow.
Like concrete, it's still there.
I would NOT like those in my pipes.

Yep, if you're using a gravel that has a clay base, you really should wash at least a bit...

I filled a half barrel with water, then used a black tub with lots of holes in the base as a sieve. Put gravel in black tub, dip tub in water and wash around, then lift out allowng water to drain out.. Worked fairly well..

Just a note on the water usage while washing gravel. Lets say it takes you 8 hours of washing to clean all your gravel for your system and you have the hose running the whole time.. Now you have your system set up and it consumes about 1/10 of the water as you might use growing your veggies in the ground..

Compare against growing your veggies in the ground where you might water them using your allocated allowance of twice a week for half an hour. Which is hardly enough to keep even well mulched veggies happy in the middle of summer.. So theres an hour of watering a week.. In ten weeks you will have used more water in your ground grown veggies than you have cleaning your gravel, and from then on, you are saving enormous amounts of water..

It's all relative...

Nice point EB. I loke cold logic and mathematical proofs

'Cept we can't use ANY water outside unless it is rain water...

Ooohh sorry... Should have put in "information correct subject to location"..

I still think the winnowing idea is under rated, people have winnowed grain for centuries...

Jus bein' diff'cult.
Winnowing is a good start, especially for the granular particles. I suspect that filtration is the next step for the suspended fines.

Sorry, thats my Grandad.



Yeh, gravel on a fly screen, give it a spray and a rough up, dump it in the wheel barrow.

Thankfully we have a 10,000L tank. No idea how much water we used, but it would have been a LOT.

I second KP et als sediment.. ahhm, I mean sentiment (heh) I couldn't dig my fingers into my scoria mud and it weighed a ton. You don't want that stuff in the bottom of your grow beds.

Sounds like the scoria must crush fairly easily when handled...

Wondering then if you put it into a mixer/trommel if it would disintergrate into dust...

hmmmm I wonder... It is pretty hard... I just don't know how brittle.

Yep, I reckon my "laundry basket in mixer" technique would not be suitable for scoria.

Probably generate silt as fast as you could remove it.

Had thought of washing some hydroton clay balls in a mixer... but decided that even with water they'd probably start to break up.

I ended up washing my hydroton like Joel suggested.... hydroton (or gravel, whatever) into a large plant pot, dunked into a barrel of water.

Rotated both directions several times, lifted drained, repeated until running near enough to clear.

Pumped the barrel water to the fruit trees.

When I was a wee'un, I spent some time at the sapphire fields in Central Qld. Water was really scarce there, but we needed it to wash gravel to pick out the sapphires and zircon. The local lore was to rig up a tank...say 1000L...with a sieve suspended over it on a long lever. Put several shovels worth of gravel in sieve, lower into tank and with an up/down or jigging motion wash the gravel. Only needed about 50mm total travel in the water. Worked a treat, the tank filled with fines and needed emptying every 1-2m3 of gravel. I have a piccie somewhere, will post it, but not tonight...working morning shift this week and I really need my beauty sleep.

Thinking about it (in the shower, I do a lot of good thinking in the tub), it was called a 'puddler' and was as simple as a sapling through a forked tree (suitably shaped etc) suspending a sieve over some water receptacle. It could be reproduced simply and cheaply in the modern ap backyard with a cheap wading pool and a sawhorse and suitable pole. Hmmm, I will call it the 'SNAG AP Puddler'. Copyright of course.

i would like to take this opportunity to promote one of the most revolutionary inventions this century.

http://www.backyardaquaponics.com/forum ... t=patented

for those who weren't around to get the reference there was a segment on new inventors where a bunch of guys were selling their "invention". aquaponics.

No pics, but I washed my gravel in the wheelbarrow, one collander at a time.