Altum wrote:

But this whole thing started with bare-root lilies.

OK, we're pretty much on the same page.

I have many plants
that take their sustenance from the water column in outdoor setups (WH,
water lettuce, elodea, watercress in the spillways, and even submerged
swordplants and grasses). The nitrogen and phosphate demand of the
plants far outstrips what the fish and foods provide. Add a little KNO3
and KH2PO4 to the water and I get healthy plants with lots of flowers.

YES! That really seems to be key. I'm not at all convinced that the
nitrogen demands outstrip what's available - I have no trouble getting
bare-root lilies to thrive in an unfertilized pond (with very little
feeding of the fish), but it may well be necessary to add potassium.

(And my bluefin killies breed like rabbits so I'm certainly not hurting
the fish.)

Frankly, I don't think they breed like rabbits at all. At the least, it's
generally hard for rabbits to breed underwater...

Liquid Miracle-Gro was mentioned as a possibility for bare-root lilies
and I stated that any fertilizer considered for fish pond water, not
soil, must be completely ammonia-free.

And I'm with you there. I missed the reference to liquid Miracle-Gro - I
was responding to specific mention of ammonium-X fertilizers which are all
available in solids.

However, it's all complicated by the fact that bacteria are constantly
converting ammonia to nitrite & nitrate, and _any_ pond can remove some
amount of ammonia from the water - which is why so many people manage to
continually top up their ponds with tap water without killing the fish.

It can, but we're back to the Bad Thing(TM).

I think we'll have to agree to disagree. If you're topping up your pond
with treated tap water you need to be _really_ careful, but I'm certain it
can be done without producing measurable ammonia/nitrite levels.
--
derek
- Unless otherwise noted, I speak for myself, not rec.ponds.moderated
moderators.