Bakki filters – looks like the key to them is lots of water flow, which is the opposite my understanding of desireable long retention time in the skippy filters. So flow is more important for the aerobic bacteria than retention time?
The data on how Bakki works has pointed in many different directions. While they all seem to get the job done it looks like they work differently depending on factors that are nor currently understood. For example some seem to out gas ammonia in a mechanical not bio way, while others seem to be more bio.
Higher flow Bakki rates may have something to do with out gassing ammoinia and maybe nitrate, but no one's proven yet that as far as I know. Basically this only concerns people who want lower nitrate levels which is not an issue for most people. For everyone else Bakki seems works at any flow rate whether it's by out gassing or bio conversion shouldn't matter much.
The info you find on Skippy is in general going to be lets say theoretical. It is human nature to build something with an expected result and then assuming the thing built is responsible for the results. The retention time thing for Skippy was always a complete fabrication. You physically can't push water thru a Skippy (a real Skippy, not things called Skippy just because it's a catchy name) very fast. So people turned that into a plus by making up the retention time thing. Repeated often. What you will never see is anyone with a table showing different ammonia conversion rates for a Skippy where flow was changed. Data has never been a friend to the Skippy filter.
A bit of common sense...bacteria that convert ammonia and nitrite are very small. To put it into a context that might be easier to understand to a bacteria a single drop of water would seem like a body of water 1/10 mile across to us. We'd call that a small lake. And bacteria can't reach out and grab ammonia, O2, carbon, etc. These things have to actually bang into them. So you can kind of see that if a cheeseburger floated several miles away from you it would do you no good no matter how slowly it moved.
Very. Even people who love their Koi more than their kids seem to dislike the noise level. Some people place the Showers inside a building. The flow can be turned down but then they would really be a Trickle Tower imo.
I think I want subtle dripping not rushing water. I guess I could damper the sound by enclosing the Bakki in a chamber like some people do.
Can still be very loud unless maybe inside an insulated building.
So with the Bakki idea the top half of the tower would be an enclosed bakki funneling into a submerged portion (sounds like a downflow skippy to me) also filled with media that then exits to create river flow BD.
Skippy is a specific filter design. A component of Skippy is static submerged media. We used to just say submerged media, but since moving bed filters came along the static really has to be added. So it would be more accurate to say "static submerged media" than "Skippy".
Are Bakkis or Skippys easier to make?
I'd say probably about the same if you're talking about say a small 3 tray Bakki vs one Skippy. But comparing apples to apples for the same conversion rate you might need 30 Skippy filters. That would be a lot more work and expense.
Are Bakkis really that much better than a skippy for biological filtration?
You'd have to do that research and decide for yourself. As far as actual data there isn't a ton mainly because few people have studied the Skippy. It's kind of like when cars were first invented people studied the differences between cars and horses. But at some point there really wasn't any point of further study. There is a fair amount of info on Trickle Towers and Bakki because they're used in fish farming.
As far as mechanical filtration goes I was thinking of a prefilter from Russell water gardens
http://www.russellwa.../Pond-Sieve.php expensive but I like the ease of cleaning and not needing to replace media.
Keep in mind this is not a sieve in any way shape or form. It is called a sieve only to sell product. They're trying to cash in on sieves being excellent filters and are today's state of the art pre-filter. It's a screen pot like is found on swimming pool pumps and many external pond pumps. Fine if that's what you want. I'm not fan because of clogging issues and what the results are of that.
I get that good mechanical filtration is a must for good bio filtration so I want to make it easy to clean out.
That's kind of another myth. Good mechanical filtration can make static submerged media work a little longer maybe. But Bakki and Trickle Tower are kind of self cleaning so no pre-filter is strictly needed. However some pre-filtering can keep the first tray in a Bakki from clogging. Pre-filtering does have several other benefits however.
I like the Oase screenmatics but they are so expensive (and probably overkill for this size pond)
And way, way over complex for no gain.
