Do others here use under-water low-voltage halogen lights in their
ponds? A few years after their installation, I found myself constantly
replacing bulbs which did not look burned out. I finally realized that
the prongs on the bulb and the sockets in the fixtures were getting
corroded. I have since re-located the lights so that they are (mostly)
out of the water, which made some difference. I have found that a bit
of emory cloth to clean the corrosion off the prongs is a simpler (and
cheaper) solution than replacing the bulbs. They still get corrosion, I
suspect because the sockets are still corroded and it spreads to the
prongs.

When I first had the pond built 12 years ago, I purchased an attractive
50-watt copper fixture, only to be chagrined when I read the fine print
that the copper was toxic to the fish. It sits in its box to this day
and has been out of mind until recently as I toyed with the idea of
just replacing all the fixtures. Now, of course my pond is filled with
water that had gone through copper pipes! My fish are just fine,
thank-you. What is the issue with the copper then?

So, in summary, are "underwater" lights that end up getting corroded,
really truly made to withstand being under water, or did my contractor
just use crappy fixtures?

Could I cause serious problems by not submersing the lights? The copper
light I have specifically says to ONLY use under water. After my
experience with corrosion, and not having a catastrophe by removing my
other lights to dry land, I am taking this instruction with a grain of
salt.

Is copper truly toxic to fish?

Regards
--
Bill O'Meally
"Wise Fool" -- Gandalf, _The Two Towers_
(The Wise will remove 'se' to reach me. The Foolish will not!)

of the water, which made some difference. I have found that a bit
of emory cloth to clean the corrosion off the prongs is a simpler (and
cheaper) solution than replacing the bulbs. They still get corrosion, I
suspect because the sockets are still corroded and it spreads to the
prongs.


You might try some silcone grease


Could I cause serious problems by not submersing the lights?


The fixture probably relies on being subursed for proper cooling.



Is copper truly toxic to fish?


Yes, however it depends on the chemistry of your water whether the copper
will dissolve into the water.

Change the lights. Light have come along way since your purchase. Its obvious

It all depends. If the water is hard then the copper will become coated in line which acts as a barrier. Soft water may absorb the minerals and yes may harm your fish. To be fair get rid and stop flogging a dead horse. If the light are showing corosion then they are fubar, bite the bullet and change them.

Agree with everything Pat said.

On Sat, 9 Jul 2011 11:16:23 EDT, "Pat" wrote:

corrosion on the prongs

You might try some silicone grease

Could I cause serious problems by not submersing the lights?

The fixture probably relies on being submersed for proper cooling.

Is copper truly toxic to fish?

Yes, however it depends on the chemistry of your water whether the copper
will dissolve into the water.

IIRC, I believe the worry is when the water has a pH of 7 or less, but one
might want to google this for sure? Most fish ponds are usually higher...
check your KH/buffering, as that can make the pH change AM to PM. You need
buffering to keep your pH somewhat stable. ~ jan

------------
Zone 7a, SE Washington State
Ponds: www.jjspond.us

On 2011-07-09 17:24:40 -0500, Robby1 said:

Robby1;929688 Wrote:
Change the lights. Light have come along way since your purchase. Its
obvious

It all depends. If the water is hard then the copper will become coated
in line which acts as a barrier. Soft water may absorb the minerals and
yes may harm your fish. To be fair get rid and stop flogging a dead
horse. If the light are showing corosion then they are fubar, bite the
bullet and change them.

Yes, that was the direction I was headed. Has anyone out there had good
(or bad) experiences with specific brands?

Thanks all for the great advice!
--
Bill O'Meally
"Wise Fool" -- Gandalf, _The Two Towers_
(The Wise will remove 'se' to reach me. The Foolish will not!)