I agree with Oliver, you have to be careful about contaminants if you
try to knock off mosquito larvae this way. The "traditional" way here
in Australia was a bit of kerosene in the rain water tank but that
taints the water. If you have a duck then they seem to do a great job
in scarfing up the larvae - we had some water standing in buckets that
always used to get mosquito larvae in them. Now that we have a duck
we don't seem to have any larvae in the water - or snails, weeds,
lettuce, spinach, silverbeet, just about anything is eaten ;-)
Brett, in South Australia _still_ hanging out for some decent rains to
fill his rainwater tank which was bone dry until a week or so ago.
-- Brett Lymn, Computer Systems Administrator, AWA Defence Industries
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"Also, it takes a lot longer to get up North ..... The slow way"
- "Clever Trevor" Ian Drury