Hawkiefriend,
You say that the pump is on the bottom in the middle with a waterfall somewhere on the edge of the pond. Do you have any other source of moving water such as another pump or air stones? Since you didn't mention anything like this I will assume the answer is no. I would conclude that there was little movement of the surface water that was caused by the water from the falls pushing a small amount of water as it fell on the surface. Most of the water movement went from the waterfall directly to the pump on the bottom. Anything on the surface of the pond would stop or slow down the surface water. Below the surface of the pond most of the pond would be mostly dead.
Mike

To a human the water looks still. At the microscopic level it's Mr Toad's wild ride. Thermal current, wind, fish and insects swimming. Take a look at your pond water under a microscope and you'll see a disco. And the bacterial world, even smaller.

The weird thing about bacteria is they may not be aware you've set up a lovely filter for them. These unappreciative creatures just set up shop where ever there's food. Pond surface, plants, plant roots, Even those tiny specks of particles suspended in the water look like planets to bacteria (well, very small planets, OK, moons, maybe asteroids).

Total surface area inside your pond is probably a few hundred times greater than the total surface area in the filter. And as matter builds up in the filter and cogs it the less of a home for bacteria. I've actually never cleaned a pond that didn't have a complete dead and cogged "bio filter". I'm sure they exist, somewhere.

Bio filters are needed for high fish loads and basically spotless ponds. They are just for the removal of ammonia and nitrate.

What's your ammonia level? Zero? If it is zero what are you trying to reduce it to?

I'd bet serious cash you could remove your bio filter completely and you'd see no increase in ammonia. Try it. I don't know your pond so there is some chance I'd be wrong. Keep the bio filter alive but separate from the pond. Measure ammonia. Ever see more than a trace I'm an idiot and you can hook the filter back up. Takes about a week to test. Do it and you will learn more about ponding than you ever will from books or the internet. Things are not as straight forward as they seem.

So, I wouldn't really worry about "dead spots". If you are they'd be very easy to test for using an ammonia test. Then your mind would be at ease.

Hawkie, we have a pond with three "bays" therefore lots of opportunity for water to get stagnant. So we put a small skimmer in on the opposite side from the waterfall, and the water returns to the pond in the three "bays". One outlet is a piece of garden hose between the lily pots, the other two are cute spitters. It helps with the fish poo not settling too thickly there - it doesn't actually stay clean or anything, but from the settling chamber we know most of the goo ends up there via the bottom drain. A lot gets caught in the skimmer sponge as well.
So you could look online for some cool spitters and a skimmer!
I do find, right about now when there are so many WH in the pond, that they impede the skimming action, and there are some WH in the skimmer every day. But I don't mind tending to that, I rinse out the skimmer sponge everyday anyway.

:) Mary

One day, Mary. One day. We have spitters and an ex-pool skimmer, but at this point we can't afford to hook up and purchase all the old pool filtration systems. One day we will.

Right now (on the primordial ooze post) I've got pics that show the WHs moved to one side, and they aren't totally blocking (on surface level) the water.

I read yours twice Mike and didn't understand it. Sorry. I'm not sure if you are saying it's OK to have the surface impeded or if it's not. The dead part confused me.

Waterbug, are you saying I shouldn't filter? That my filter will NOT be one day the place where the bacteria will live? That everyone who believes in the Skippy filter is wrong?

I know I don't have an ammonia problem. But filtering is good for other things too, no?

Hawkie, some of the confusion is because there are two kinds of filters.

1) Bio filters are needed for ponds with a lot of fish, because they excrete in the water and that produces ammonia. A bio filter provides surface area for bacteria, which break down ammonia (poisonous) to nitrite (poisonous) and other bacteria that break down nitrite to nitrate (harmless). The nitrates are plant food, and WH etc. use it to grow big.

2) Mechanical filtration is needed to remove particles, for example the green goo(fish poopoo) that gathers on everything in the pond, mostly on the bottom, but also other bits, leaves, etc. The sponge in the skimmer, the roots of the WH, and the filter medium in the bio filter all work as mechanical filters. Vacuuming the bottom removes these particles, so do bottom drains and settling chambers. You can rinse out the ones that are NOT used as a home for the needed bacteria.

The skippy theory has a few holes in it, for example, the debris that it mechanically filters out (while doing its biological job) does NOT completely disappear and change into a bit of sand. The goo seriously clogs up the bio filter until the water runs only through a few channels. So even the skippy needs an occasional cleaning. If you have town water with chlorine, don't use it for rinsing, just scoop a bucketful out of the pond. Gently plunge half of the filter medium up and down in the bucket, put it back, and wait a few days for the bacteria to recolonize; then repeat with the other half.
We only do this at the end of the year now that we have the settling chamber, and we can drain the goo from its bottom with a whatchamacallit valve thingie (DH's job). So, not a very involved job for me! I love low-maintenance ponding.

:) Mary

We have a large Savio filter. We do have that whatchamacallit valve thingie (technical term, LOL) that drains the filter into the "jungle" behind it.

There is no bucket that would be large enough to clean our filter media in. We have the Savio Springflo bio-media as well as several thicknesses of Matala mats.

My pond guy hosed it all down twice with hose water. The friends here said NO! No bacteria will colonize there if we keep cleaning it out. So I am waiting to see what happens.

I guess I need to clean the pond, and maybe DRAIN the filter sometimes. Living and learning.

WH roots help filter the water, dreate o2 and shade the pond thus reducing algae. I wouldn't worry about "dead spots" if you have pond plants giving off oxygen.

Hi
Check out some of floridas canals lol Talk about dead spots. You can almost walk accross them.lol
I grow them in my ponds because I find NOTHING comes close as a water conditioner. I believe they are illegal
so don't tell anyone lol
Aren't they listed as weeds in Cal. also??. Only thing I've ever found that affects them is cold and running water. and KOI ,love to shred the roots But GEEE thay are a fabulous filter. gary

I know mine really slowed down my stream.
My ONE hyacinth turned into hundreds this year. The ones in my stream built up huge root systems, gather ditritus and actually backed up the stream. There was also some backup at the drain edge to the upper pond into the stream. Other than that, I didn't have any problems.

My friends thought I was joking when I said come and take as much as they wanted, but I took the water hyacinths out of my pond three times this summer... one time I took over 250 and put them in my parents' pond. I took at least that much water lettuce as well.

And... my koi don't bother them. That may be because my daughter feeds them probably six times a day

Chris