Backyard Aquaponics
A place to discuss aquaponics

Its not only about surface area but also about protected surface area like in the case of these mb3 and k1 media

Not sure I'm convinced of that Swede.

Sleepe,

what convincing do you need? will the comprehensive research done on k1 by the waste management space be sufficient?

No.

I have raw pellets in my MT system outside. Great surface area, not nearly as good at nitrification. The surface is too smooth and allows the bacteria to get knocked off too easily. The K1 has tiny ridges as well as the internal spokes that don't get hit as they tumble around.

You can use sand too- lots of surface area. Just be prepared to clean the filter daily, and waste a lot of water.

There's a reason why K1 is used at every almost every major RAS and most newer sewage treatment plants. It works.

Sleepe, I guess it depends on how you are usung the media. In a mbbr i would go with a k1 type media. There are filters were beads would be better. But since we are talking MBBR my vote goes to k1 style media.

Coach, I modified my RFS hope you don't mind me sharing a picture here?
I am not convinced that it has improved anything from my previous design but here it is.

You have the saw tooth attached to the outlet,but you still have water rising up pass the baffle which could actually increase the water flow in that area,water will take the line of least resistance so will flow and semi buoyant solids will flow through this area rather than following the flow down from the baffle and settling,with clean water going over the saw tooth,wouldn't it have been better to have that saw tooth outlet tighter to the baffle to reduce this ? It will be interesting to see what happens.

It looks good swede. Maybe making smaller cuts in the weir?

+1 - I think the water should pass over the saw tooth weir before it can exit (of course that wouldn't be right with this particular setup). I like the design otherwise. What size container is this and what's your flow rate through it? It looks like it's working.

Nothing says that the flow has to exit over the weir toward the outside Swede. Try cutting the hole in the center of the bucket your using for the saw tooth weir to exactly the size of your stilling well pipe. The water will be forced to go over the weir from the outside to the inside and your exit pipe is perfect for this

So the flow is as follows
1. water comes in the center 3/4' pipe.
2. Water is forced to go downwards by the 4" stilling well
3. Once it's reached the bottom of the 4" pipe it has to go upwards
4. goes upwards and passes over the jagged tooth weir
5. exits through the side outlet that's attached to the jagged weir.

I am not sure but I think I should have made the jagged tooth weir taller and laced outlet further down the weir( not sure it would have mattered. Also smaller teeth like Coach suggested would possibly have helped trap any floaters a little bit betterthan what it's doing right now..
The weir has a tendency to float which is prevented by the 1/2" pvc pipe I drilled holes for in the 5 gallon bucket running across the stilling well to hold it down.

It sees a flow of about 121GPH.

Thanks.

Hmm, so I'm missing something and I think maybe Andreas and I are seeing the same thing. Is there a gap between the pipe and the sawtooth weir bucket and if there is, what keeps the flow from going this way where there is no weir? If there isn't a gap is that a uniseal?

It's hard to tell, but from Swedes description, I thought there was a universal there??

Yeah, it sounds like there is something there but I think because of the reflection from the bucket handle on the right side and across the water in the middle, it looks like there isn't.

Scotty, you missed that mistake. A unisel, not a universal. That's what happens when you type on a tablet. lol