Backyard Aquaponics
A place to discuss aquaponics

Rupert, The system is not finished yet. just the plumbing to the sump and the sump to the tank. I was able to wash the gravel in the GB's and let it drain to the sump. But it is not very succesful in cleaning the gravel. The water in the sump will be used on the garden. I will build the filter first and see how well it works before I run the system completley.

AP

Depending on the type of pump you have, that red grit can really be hard on bushings.

Does anyone know why dust actually sticks to gravel when its dry (?electrostatic effect).

Entropy... It continually breaks down coating the surface... Really? I 'm not that sure, but entropy is the easy, correct, cop out answer...
Like why do ropes tangle? Entropy. The continual march of disorder.

Entropy is more the "loss" or decay of energy within a system isn't it.

Such decay may utlimately lead to increased randomness and unpredictability within a system...... i.e it will tend toward disorder and chaos....

The tendancy toward chaos is inherent within systems according to "Chaos Theory". Entropy is just one of the mechanisms used to explain the unpredictability of seemingly random events within a system.

Ropes tangle because people do not coil them in a figure eight.

Rocks do not break down that fast and you can hardly consider their dust to be disorder (you have been reading too much sci-fi) .

If we could find the reason dust sticks perhaps there is a way of making it unstick (without washing) .

Now there is something to get your brain around!

Sssshhhhh! Don't let LKB hear you, He will be most upset

the dust is mainly clay, which absorbs moisture so well, hence moisture in air. Fix = heat and shake through a screen. Really painful and still needs washing anyway. Wash and Floc the way to go

hehe too much scifi :-) still, if rope is left neatly coiled, not in a figure 8 what actually makes it move and tangle? if you pick it up 5 minutes later it's ok, but next week? Tangled... all that is different is time. Entropy it is. If the rock doesn not break down then the disorder picks up dust from under the gravel and makes it redistribute :-)
Hey it's my theory and it's so vague and light weight, it's really hard to refute - unless you state it's vague and lightweight

from my early rock climbing days, and probably a very bad explanation but I will domy best: A rope coiled in a circle or similar will twist as you coil it because there is increased tension on the inside of the coil. the rope twists naturally to releive this tension. It is this twisting of the rope that causes it to easily tangle along with the vairied tension throughout the coil. As the coil is unwould the twisting of the rope now under less tension twists into itself causing small loops often inside larger loops which is result in a tangle.

It's Maxwell's Demon's evil twin. Also takes well-adjusted AP systems and tweaks them so they fail in interesting ways (usually when one is off for a few days). Although you have to wonder where it can find the free time with all that sticking dust specs to gravel.

Bazz

Clay is just fine rock dust take your point though re the water absorbtion.
With the hot/dry we get here in summer the gravel is still covered in dust, which is the main problem in systems. and does not all come off ie its somehow attached. If it wasn't you could just get a garden blower and blow it off.

Thought about a barrel with water and a shallow laundry basket (Scott). Fill with gravel suspend in the water, pump compressed air in the bottom of the barrel and cleaned. Even if you introduce floc into the water the second time you do it the gravel will get coated because the mechanical action of the compressed air will put it into suspension again (I think).

What sort of floc were you thinking about? have to be non toxic and cheap.

KP get a power cord the one with the stripe on, coil it up then look at the stripe. Besides you have a dog and unless his/her name is Entropy you rope probably got Rovered .

Sky

Nice explanation, I get a clip round the ear (metaphorically speaking) from an AB if I don't coil things properly.
Missed your post as I am emptying and cleaning a 4' fish tank between posts (carpet is still drying from the natural disorder of the Universe, well me actually as I didn't notice the siphon had somehow jumped out of the esky)

Sheesh Rope, now they are gonna coil you to increase tension...I thought all it needed was a couple of well placed phrases to get you all coiled up