Backyard Aquaponics
A place to discuss aquaponics

I'm now running a small raft DWC and want to add an SUF, but can not seem to locate the description. Anyone want to help a guy out?

Inflow at the bottom, outflow at the top surrounded by your floating media and you also want a drain. Screen everything to keep media in but still allow solids to enter. As your media blocks with solids the water level rises and that's your indicator to clean the filter. See Dasboots thread I think he has some pictures of how he did the outflow. I come in low and then use a 90 degree elbow to a vertical pipe topped with an atrium grate for my outflow - it's roughly centered in the barrel. The inflow needs to come into the barrel without disturbing the media layer very much. I don't like stirring up the bottom either because I want more solids down there than trapped in the media layer but it's not a huge problem. The reason for not disturbing the media layer is that this can cause channels where solids can bypass the filtration. Sorry, no pics this time

Thanks Scotty

It sounds like if I turned the bubbler off in my MBBR it would be a SUF, especially since that is how I plumbed the MBBR.

I remember Scotty435 you suggested I create a static portion in my MBBR and a moving bed section in the same barrel. I may be finally getting it. Perhaps, I should pay more attention? For now if what I am suggesting is even faintly true, I can continue as planned?

Yup, if your MBBR inflow is down low, and outflow up high, if the air is turned off, it's a SUF. Like Scotty said, add a drain at the bottom for cleaning. I have been cleaning each SUF every 3rd day now. Only feeding 260 grams a day. Dash boot cleans I believe every 4th day. No idea how much he feeds per day. He uses bottle caps and I'm using K2. I'm thinking the K2 will clog quicker.

Check out how clear the FT water is...

Sounds like you understand it Brian . There are all sorts of things you can do, the combo SUF MBBR filter is one. Obviously this isn't plumbed but here's one I'm getting ready where I'm trying to force the solids down along the side before they either settle or go back up into the SUF at the center (might be a swirl as water enters or more likely just send the water straight at the center bucket -


The inside


Showing the outside with the upper hole for the inflow and the lower for the outflow


With cover to block most of the light.

Oddly enough this design will probably also work as a Mineralizer by aerating everything and then when you want to decant shut the air off and after it settles let in some flow, trying not to disturb the solids that have settled. The media in the center works like as a SUF to filter the solids out as the water flows out of the mineralizer. If it works (and it should unless if gooks up too much) then it's a simple solution (it's nice that it does it's own final filtration and no piping back to another filter). No reason you couldn't use airlifts and a vortex like Andreas with this either, although you'll probably have to aerate the center where the media is somehow. Having holes along the sides of the bucket higher up might allow the vortex to affect the center section for some aeration .

The downside of this SUF design is a lower filtration surface area within the barrel so it will likely block up faster.

This is a small filter and I'm not exactly sure how many fish it could handle on it's own but I'm guessing it could handle all filtration in about a 1500 gallon pond (maybe around 75 to 100 gms of feed per day). I'm going to try to split the system between plant and fish and I'm not expecting the SUF to do all the filtration (really just solids filtration). I'll be using an MBBR for additional biofiltration and will probably waste some water to the plant part of the system weekly so the filtration should be OK.

The outer is a 20 gallon sump basin made from the same sort of structural foam as the Rubbermaid stock tanks and the inner portion is a food grade 5 gallon bucket and a net pot joined. I haven't decided on the flow but here are the options -

1. The inflow will probably not have an elbow - the water hitting the outside of the inner bucket will kill the velocity and spread the flow. The flow goes around the bucket both ways and meets on the back side of the bucket. I did something like this in the Recirculating Aquaculture System and it worked pretty well.

2. The inflow will have an elbow and the flow will swirl in one direction. There may not be enough room for a 2" elbow to easily fit but I've already thought of some possible solutions to this.

With either method you'll get large floating solids in the outer ring that can be removed with a small net or scoop. Solids usually float up like this if you don't flush the tank every few days.

Boss,

My phos level is of the charts at > 10. I'm having a slime or some brown filament algae growth issue in the SUFs. I think the slime or algae is due to the high phos and is clogging SUFs quicker than it should. Each of the SUF started with 4 cu ft of k2. I've removed 5 gallons worth from the first with not much improvement. Not wanting to try too many things at once, I'm waiting for the phos levels to drop so see if the slime/algae decreases and thus increasing flow thru SUFs longer thus more days between cleanings. We shall see, time will tell.

PS I won't go back to cloth or netting..... they were a PIA to clean. This k2 with some air, cleans itself nicely.

Thank you both gentlemen