Backyard Aquaponics
A place to discuss aquaponics

Scotty I think you might be right about it being hard to prevent the media being drawn up, my K1 is 10mm in diam., if I covered the elbow with a grill or an end cap with 8mm holes that would stop that problem.

I think a grill would be more efficient than the holes, it's hard to drill holes in such away that you have minimal plastic left without breaking through from one hole to the other, with a grill there's more hole than plastic.

Scotty I've always drained the solids from my filters with the pump running, maybe if I turned the pump off before draining each time that might drag the solids though the outlet a little better.

Keeping the air running would keep the media suspended and just stopping the water flow I think that might help the draining process, I'll try that and see if it makes any difference.

I noticed Paul used his MBBR as a trickling filter and Rob repeated this with great results as far as clearing the water of suspended solids. I think they both used pumps to clean out the bottom of the filter tank so you may already be on the right track using the pump. There are a couple of videos out there showing the process.

I've now tried draining the solids without the pump running and it appears to remove more solids that way than with the pump running.

Being winter here now and the fish are not eating there's not a lot of solids to remove so it's probably not a true indication but it appears that it is a better way of draining the solids off.

I'll run with that without changing anything until I notice any buildup or drainage problems.

Interesting, keep me posted.

Thanks Scotty I will do.

I'll look for those videos, I've seen Rob's but I don't think I've seen Paul's.

The knowledge sinks in a lot better when you're actually chasing something other than when you're just viewing for pleasure.


What I think is happening with the solids removal is that while the pump running it keeps the solids suspended and with the pump turned off they settled on the bottom and are being dragged from there.

That seems likely. Running the MBBR as a trickling filter looks to be an effective way of trapping suspended solids (at least in their designs)

Here's Paul's video - http://www.youtube.com/watch?v=i0TPeemBsqE&list=PLG2PbZ8XM4VAo-oI00_W7V9zE2x-Lf1r6

and for those who havn't seen it, here's Rob's - http://www.youtube.com/watch?v=7DhypNPRdC0

Cheers

Thanks Scotty

Thinking about the venturi in the MBBR and I'm wondering if coming up through the bottom wouldn't be the best way to do this. No curves in the pipe after it enters the barrel and could point it straight up near the middle seam. If my venturi isn't perfect maybe I can just move it closer to the top and get better bubble action? Anyone have any thoughts about this before I head to the store and look into disconnects or screw fittings for below the barrel?

This is a mazzei venturi manifold and looks like it has potential for dialing in the setup of a venturi. You can regulate the water flow through the venturi as well as the air flow (they're using is for Ozone injection). You don't need anything this elaborate for the air flow though (in our case a small valve on the airline should be enough). I could see where this might help adjust the venturi for use at different depths or to get different bubble sizes. I'll be using an airline valve and depending on how my home grown venturi install goes, I may try something like this manifold as well. Thought someone else might need the info whether I do or not.

http://www.youtube.com/watch?v=2Cggk6rl1GE

Cheers

These might be of use to the Aussies out there for aeration or mixing - http://www.toro.com.au/product/toro-mazzei-injectors?c3=injectors

Time for an update. Hopefully no one will see any major mistakes but it's still a work in progress.

The inside of the RFF with the bucket removed. The inflow is in the middle. The pipe on the lower left goes to the MBBR while the one on the right goes directly down to the sump through the center drain. The pipe is not attached at the drain and can be lifted to drain from the bottom of the tank. I still haven't tried it to see how well it holds water when draining from the bottom. The pipes under the barrels are still being tinkered with -



Inside the MBBR as it is so far. I haven't added the inlet or outlet covers or finalized where I want them yet. The venturi aerator is not installed yet either. The outlet is at the top of the photo and the inlet is at the bottom.



This shows the uniseal for the venturi supply and the hole through the wood floor down into the sump for this piping. It also shows the only direct join between the two tanks. I will either add another ball valve here or cap the intake in the RFF barrel (which would also involve lowering the RFF level slightly when it's operated by itself, since this pipe helps support the center drain pipe - see cable tie in the first picture). I had to put the uniseal inlet higher than I wanted to allow for the curve into the tank and hopefully a disconnect of some kind.

One more photo for now. This is a shot of the outflow from the IBC into the RFF. This has a single union ball valve and a disconnect union (forget the actual name at the moment). You'll also see an overflow skimmer outlet from the IBC behind this. I was originally going to plum this into the MBBR but I'm having second thoughts because I get floating junk from some of the trees around here. I do need an overflow but space is tight and I'm open to suggestions on what to do with this. Paul used this sort of skimmer device in one of his videos.



That's it for now. Cheers.

I decided to run the overflow/skimmer off the fish tank to the MBBR as Paul had done but into the top instead of the bottom (just no way to get down in behind and set it up there). I'll have to put a screen over it to keep any flowting bits out. It shouldn't matter where this water enters it will be forced to the outside of the barrel and down because of the venturi causing water movement.

Got almost everything done, some connections glued some not. I found a leak from one of the bottom drains - turned out to be from the fitting not the seal. It was the fitting I had drilled to put a cable tie through to hold down the endcap. It turns out that the wall where I drilled it was hollow so the holes drain right into this hollow area. I'm going to seal it tomorrow, probably with silicone

The manifold is ready to test once the drain is sealed. The venturi is installed in the MBBR and the fitting for the fish tank venturi is ready once I get the venturi itself done.

I still need to do the pipe covers for inside the MBBR to keep the media in. No media in there now - I'm going to run the system though into the fish tank and flush all the garbage into a paint strainer for removal. Once I've done this I'll get the fish tank venturi ready.

The piping under the bottom drains is ready to go as well. Put some media into one of the AP media beds to inoculate it with bacteria - won't have a lot of exposure but some. It's tied in a paint strainer bag and partially burried.

Will probably get this tested within the next two days depending on the silicone

Cheers

System is running with the RFF but not the MBBR. Bypassed it by opening the bottom drain of the RFF and shutting off the venturi. Water never rises high enough to make it to the MBBR this way. I left the overflow from the fish tank open and the MBBR bottom drain open just in case but it's adjusted so it won't overflow unless something gets blocked.

Tried plugging the leak in the bottom drain of the MBBR by inserting a bolt through all the holes - as tight a fit as I could get it but not good enough. I'm thinking pvc rod or pipe with cap might be the best fix since it will lock the cap on at the same time.

Some pics -

The inlet to the IBC is covered with a paint strainer to capture all the bits of plastic that were in the sump from drilling and cutting the tanks and pvc. The center connection is the overflow/strainer and on the right is the top of the SLO which goes straight down into the corner and has an atrium grate for a cap.



This is the RFF - Since the tanks are high the water level isn't as high up in the bucket as I would like but the flow is steady. I'll have to wait and see how it's doing.



On the left is the RFF outflow bypassing the MBBR (The outflow for this is open but nothing or almost nothing is coming out - it's on the right). Beneath this is the pump manifold. The large line between the two tank outflows goes to the MBBR venturi and the Fish Tank. There are two other 1" lines to the right of this. One is for the sump circulation and the other is for garden or other use. I don't think this will be enough to run the DWC beds and I may setup another pump to do this but we'll see. The pump is a Laguna maxflo 1350 gallon per hour (just going from memory here so don't hold me to this). Neither venturi is running and this will probably reduce the flow a lot when they are.