[Sue Deacon]

I know this might sound like Muppetry of the highest order, but is it safe to use copper pipe (in sections, as weights for oxygenators) in a pond with fish?

I know most of our household water comes in copper pipes, but they used to use lead and we all know how dangerous that is!

I want to stop my oxygenators moving around the pond when I skim off pine needles. OH has some odd bits of copper pipe that I thought might provide just enough weight.

[Good guy]

I'm not a chemist, so maybe I'll get shot down, but here's what I think:
If your water is acid then a little oxidation will take place but as far as I'm aware, once there is a layer of copper oxide on the surface of the metal, further corrosion is unable to take place. I doubt whether the tiny quantities released would be toxic to your fish. I'm sure you could use lead fishing weights, either, as lead resists corrosion in a similar way.

[tagwex]

You could use empty Heineken bottles instead!

[Blowin]

If you're worried, Sue, why not play safe and use suitably sized stones in bits of plastic netting such as come off fruit and veg in the supermarket? You'll almost certainly find other uses for bits of copper pipe.

[kindredspirit]

You can use old spark plugs. ('cos I used to use them as weights when sea fishing.)

[Good guy]

I think you might have sparked off a new re-cycling craze.

[Good guy]

Would it not be better to use goggles rather than spark plugs when see fishing?

Otherwise, your experience might be electrifying rather than edifying!

[vulkan]

Sue, you are right when you say that household water comes through copper pipes and that lead is dangerous.
HOWEVER, that is looking at it from a human perspective. What is safe for humans is not always safe for fish, and in this case, copper in tiny amounts can and does kill fish.
If copper was safe for fish why is it that you do not see things made from copper for fish tanks etc. Copper is often used in water features, because it does not rust, but water features do not have anything living in them. If you want weights for plants use stones.

[Sue Deacon]

[Good guy]

I use veg net bags to hold straw for the pond and I put a couple of stones in to sink it.

[tagwex]

Awwwe shucks Sue you say the nicest things.
What would be wrong with them anyway? They will sink won't they?

[Good guy]

RE weighing plants down in a pond:

I include approximate values for the specific gravities of the various materials proposed so far:-
Copper 8.9
Lead 11.3
Steel + ceramic 7.6?
Stone(s) 2.4 - 2.6
Glass 2.6

It appears that in terms of maximum weight and minimum pollution, the spark plugs have it.
Heineken bottles are no more efficient as weights than common stones but take up a lot more valuable pond space. As the production of glass from virgin materials requires considerable amounts of energy and produces concomitant quantities of CO2, the responsible gardener would return his/her bottles to the bottle bank.
Pebbles have a zero carbon footprint and the net bag would probably go to landfill if not re-used.
Draw your own conclusions, but please use a pencil made from re-cycled CDs and a re-purposed paper bag.

[tagwex]

Says the man who was raving only a few weeks ago about some sort of a glass feature in a pond in France........

[Sue Deacon]

What HAVE I started?!

Even my computer is having second thoughts on this subject. It sent the last two posts straight into the spam file.

[tagwex]

I know a few people who should be similarly filed!