Aquatic Plant Stimulant that you can buy at your local pond supply is (most
likely) nothing more than a trace element mix with chelated iron.
You can find the same thing in a concentrate at any decent garden center,
for a lot less $$$.
I use Dragon brand 'Liquid Chelated Iron', which costs about $9.00 per
quart. The label directions for land plant or lawns is 1 tablespoon per
gallon of water, which is then sprayed on yellowing plant leaves.
I add a tablespoon or so of concentrate to my +/- 2000 gallon pond whenever
the aquatic plants look like they need a boost. If you want to use a more
scientific method for gauging how much / how often to add, you can get an
iron test kit for aquariums. The percentages of iron to other traces is
usually about the same in most brands of supplemants, so if you keep the
iron level in the desired range, the traces will be at a good level as well.
The Dragon product has the following %:
Magnesium 0.50%
Sulpher 3.90%
Boron 0.02%
Copper 0.25%
Iron 6.00%
Manganese 0.25%
Zinc 0.50%
Check out the label on pond specific trace mixes, and I'm pretty sure you
will find similar proportions. Some may also contain potassium, which you
don't need, as you are already adding potash.

HTH,

David


"NJ" wrote in message
...
The pond has been great all summer, but suddenly my water lettuce is
yellowing, even the "pups". All the usual levels continue to be fine. I
have added potash every two weeks and have not done anything different.
Clarity is good; no algae problems; fish health great (even had some fry
show up this week!).

SO!

1. What might be causing the water lettuce to yellow?
2. Would adding the product Aquatic Plant Stimulant help,
and is it safe for my 4 sarasas and 1 goldfish?

We are scheduled to be part of the local "Battle of the Ponds" tour this
weekend, so I need some quick assistance.
Thanks in advance!

NJ
zone 5b