Great overview Reed.
I apologize for not bringing sump into this discussion. Sorry, I'm a pond guy that deal mostly with closed loop systems.
History of our journey:
A few years back,
Reedmaster16
,
H
HULON
,
cigars
,
C
Chicxulub
and I were messing around with a glass filter. Same as a sand filter but filled with crushed glass. The idea is to use water change water to backwash the filter. We all got different results due to the different fish and load we put through the filter.
As the hobby evolved, less maintenance became key. Popularity of the K1 reactors and bead filter (Ultima) grew.
kendragon's observations:
In the koi hobby where I started, color, size, and conformation are show winners.
Like MFK, the filters evolved. Over a 20 years period, I've noticed differences in kois based on the filter used. As I mentioned earlier, the simple traditional in-pond filters produced better looking and healthier kois. Several members resemble this effort (duanes and TLkmDN).
What is a traditional in-pond filter?:
It is simply gravel with flow pulled through it. I've seen them in a pit and even spread over the bottom of the pond.
Where there is flow you will find aerobic bacteria and dead spots with no flow, anaerobic bacteria.
So one should not be so quick to discount under gravel or sponge filters. Just remember that the media is held in a large volume of water and not in a reactor.
Balance (as Reed mentioned):
I do believe that bacteria colony will grow to the level it is fed. So the filter should be big enough to support growth. Some filters are great for juvi state but once they get to monster size trouble starts.....filter crashes. Many filters are great for nitrite but on the flip side are nitrate farms. One must figure a way to balance this.
kendragon's theory:
Monster fish can grow bigger, healthier and more colorful with the use of anaerobic bacteria.
There are reactors and magic beads that grow anaerobic bacteria on the market but I wish to mimic what I know about koi ponds.
Is bacteria sensitive to light? Yes, so I have a closed chamber.
Is bacteria sensitive to oxygen? Yes, so I have a high flow through the aerobic media but bypasses the anaerobic media.
Does filter cleaning stress the fish? I believe so. Chamber is never backwashed. High flow keeps the media clean. Backwashing will disturb the anaerobic area. Pump is never turned off, even for WC. Tank water volume is small so what's in the tank the fish will feel right away.
I do not have a drip system because I believe the filter should do all the work. I do not prefilter because feeding pellets minimizes waste and besides you can't separate fish urine. All comes back to eliminating NITRATE. Keep in mind....I'm only speaking for fish not rays. Reed or ray guys can chime in on rays.
Porous ceramic media should maintain thin film on the surface to allow the lower oxygen center (anaerobic) to react with the water if it is to be used as a two in one media.
Like Reed said, hard to believe crashing shower (high in oxygen) will allow anaerobic growth. Theoretically, the center sees no flow so no oxygen enters but still sits in water. Very important to keep the surface clean in order for the center to work. So do you stack them stream wise?
I will show pics of my filter later.
Thoughts?