Activated carbon (your charcoal) doesn't last forever. It should be replaced regularly (when it stops working). It is good for stains from tannic acid and odors but doesn't do anything for particulates or algae. A way to refresh it once is to crush it slightly to expose new surfaces. Molecules adhere to the surface of the charcoal.

You haven't given us enough to determine where the cloudiness originates. Do you use a test kit? This can narrow down the cause. Have you checked to see if the cloudiness is the presence of particulates in the water? To check this scoop up a jar of pond water and let it sit for a couple of hours. Particle debris will settle out or rise to the surface. What color is the cloudiness? Is there peat in the potting soil? Do the fishies dig in the pots? Is there algae present? Do you have rocks on the bottom? It can collect and hold debris and fish poop that cause water problems. If the rock is limestone and the water acidic, the limestone will increase release of CO2 that will cause a white cloudiness to the water. This can eventually hurt the fish. There could be other concerns or a combination.

Many of us have great success with using quilt batting as a filter material.

Hi
There are at least two basic kinds of ponders/ aquarists
"Chenists" and "natualists" lol Much to be said for both approaches but both have limits
No matter what you do the water will undergo a continuous "cycle" generally IME the first major one requires around 8/10 weeks dictated by the balance between plant and aninmal life ,temps and volume of water.
Sounds like you have a good mechanical/chemical approach to the management of the water just be patient.
IME the best filtration method ever invented is a balance between plant and animal life. Any body of water will arrive at that balance no matter what you do anyway.
I don't use any mechanical/chemical methods at all just regular and extensive water changes .Don't know if the water is clear of not as every square inch is covered with robust plants have way more fish than should be in that volume of water.
So choose your method none are perfect for sure lol gary

thank you for your response. I do use a very simple test kit that tells me the nitrite, nitrate, ph, and chlorine. All parameter are within the acceptable range. I believe the cloudiness to be from the introduction of the water lily. I stirred up the bottom a bit when putting it in also the fish enjoy "playing" in the pot. As far as filter media you recommended - quilted batting, Would that require the addition of bio balls or can it stand on its own. What is the maintenance on the batting. Thank you for your advice. This is my first pond and I already want another one. My wife is afraid that we will not have any grass left!

Those are two totally different subjects The batting is for mechanical removal of particulate matter in the water. It is simply a sieve that catches stuff larger than molecules. Microbes live in it, but they live every where in your pond.

The bio balls don't do anything for particulates. They simply provide a living space for microbes that consume nitrates in the water. There are many substitutes for them such as plastic scrubbers, plastic forks, cut up straws, lava rock and many other objects that don't decay in water. They all provide lots of surface area.

I don't like the lava rock. It collects too much gunk and is hard to clean and is very heavy and expensive. I do have a layer of scrubbees under the quilt batting. I have never had to add store bought microbes. There are many threads on a search that discuss different bio objects. Bio balls are rarely mentioned.

Some people use a single layer of quilt batting and rinse it or replace it every day or two. I just refold the whole thing to fit the top of the Skippy, which gives me about ten layers. I don't have to change it at all during the season unless the critters decide to play in the Skippy. All bets are off then.

You might want to do a search on quilt batting, scrubbees and some related subjects here. This can be a definite Hot Topic.

What's grass? You mean that stuff that covers 10% of our yard that my DH hates to cut?