Hello Bill,

You've come to the right place!

I'm just going to ramble here until the real
experts show up ;-)

Plants are valuable in the pond.
They help keep the pea soup green water at bay.
The more plants the less 'food' for the single cell
algae to feast on. The plants are converting ammonia
throught the nitrate/nitrite (or the other way around)
into useable stuff for the plants.

The froth in the koi pond may be caused by the koi
spawning or frogs and/or toads.

The filter certainly is removing
something - I got quite a lot of crud out of it.

We call it mulm - all the stuff that the fish produce and whatever falls into
the pond. The foam rubber is acting
as a mechanical filter.

The thing that I think almost anyone on rec.ponds agrees on is that a DIY
filter is much better than almost any commercial filters out there for most
ponders. And is the cheapest way to do stuff.

Our 3,000 gallon pond with koi and goldfish uses a 150 gallon stock tank,
simple upflow through vinyl screening, acting as both a mechanical filter and
biological filter. In the summer it is topped with floating plants (water
hyacinth) to further filter the water. The thing can run for a year and when we
clean it everything smells river water sweet which tells me it is working fine.

The biggest mistake most ponders make is to overstock their ponds and then
overfeed their stock. It takes a real deft hand to managae an overstocked pond,
most of us can't do it and end up with pea soup water and dead fish.

Now I'll step aside for the experts....


k30a