Backyard Aquaponics
A place to discuss aquaponics

I promised the grad kids I'd take them fishing the first monday after school was out. We'll just focus on little sunfish for the time being from shore or a dock.

So I've got 5 days to come up with a fish tank for their trophies.

I wanted to do a ferrocement tank after watching Cottons work but can't afford it right now. I did some additional research and found how to make a tall tank for my basement greenhouse;

http://www.youtube.com/watch?v=mVhnDGVBDrU

But again the money thing.

I then went through my "inventory warehouse" and found somethings I might be able to cobble together for a modest size tank that would fit the basement. Some used cattle panels, fiberglass cutouts, an 11 foot air ring pool and some high tensile fencing wire. Next I felt like I had to do some 3 D "modeling" to see if the large tank would fit. I can squeeze it in but that's going to take awhile given my latest higher priority honey do list. So I resurrected last years 50 gallon tank and a couple of grow beds. Again some more 3D modeling was in order. Now it looks like the tanks will fit and I'll put legs on the grow beds and do some plumbing to have a place for the kids trophies. Once the big tank is constructed and tested then the 50 gallon setup will be a hospital tank or a "trophy" tank.

I am starting to plumb my blue barrel grow beds. Some will be constant flood type grow beds.

Instead of the usual syphon systems or the constant height stand pipe " in the barrels ", how about placing the constant height stand pipe out side of each barrel? What about "drag" thru the media profile in the barrel halves?

As far as a media guard, I could lay it down like Travis does in his barrel ponics or just place it verticle by the outlet. Hmmm maybe do one of each for comparison?

Opinions please!

Roots. They are your enemy in a drain. So, you still want a vertical media guard so you can keep your drain clear.

Like a loop syphon you mean? I think Rupert of Oz still has an internal (vertical) media guard with his:

viewtopic.php?p=198584#p198584

Thanks Ron and BIF,

Media guard inside like Rups?. That's what I'm thinking also.

I'm thinking of putting the stand pipe outside in place of a loop syphon to make it a constant flood.

Not sure how you'd construct that, how would you catch the water as it overflowed the standpipe?

How about a loop syphon, but with an air hole at the top to break the syphon?

Or an external slo like I've seen done for ibc's?

Neither would give you the option of running timed flood and drain though...

But I like the idea of an external SLO style with the option of a cap on the top tee to switch to auto-syphon mode

How about a by-pass at the low level, with a ball valve to drop the flow right down? Could get you the best of all three worlds:

Cap on, valve closed = auto syphon.
Cap off, valve closed = constant flood.
Cap off, valve open a touch = timed flood and drain.

Other combinations get interesting, can an auto syphon work with a small hole (bypass) to let the bed drain when the pump's not running? Or does that tend to mess up the syphon?

I might need to draw this one...

Yes many people run a bell siphon with a small hole in the bottom of the stand pipe in case power goes out when the bed is partly flooded, it will let the bed drain, that won't work on an external set up though well maybe the valve option but it might also mess with the siphon functioning depending on how everything is hooked up.

Any of those options I would still strongly suggest you still need a gravel guard around the drains in the grow beds so you can keep the gravel, media and roots cleaned out of the plumbing.

Thanks to everyone for suggestions. I decided to change things up. I went with the internal SLO and media guard

Before you add media, you may want to reconsider those media guards. If I could go back, I would not use drain line. Too little flow through it.

Since everything is gravity flow from the fish tank SLO I decided to just drill a 3/8 inch hole in a cap for a valve. Still tweaking and trying to balance the flows into the grow beds. Also I ended up with a 50 gallon fish tank and 6 halves of 55 gallon barrels. Had a couple of leaks during the build but water leaks and pump test are ok now. I'm ready for rock on Friday (in 2 days).

Now I'm wondering how much and how often to dose the system with ammonia?

Any suggestions?

Thanks

add some slots to the guard

Ron,

What would you recommend for media guards? More holes? Different material? Lay it down on the bottom like in barrelponics?

Keith,

Thanks , maybe I'll try that on 1 growbed and see how it goes.

I've got 2 days to make changes.

Little, (you're aiming for 2-4ppm) and not often (add it once, wait however many weeks it takes for ammonia and nitrite to drop to zero, only then consider dosing again.

It's very easy to add too much ammonia, which will result in the cycle taking longer as (a) there's more to process and more importantly (b) the ammonia could inhibit nitrospira growth.

Add a little, wait for it to disperse, test and only then add more. Everyone's ammonia will be a different strength, but as a guide I only needed about 10-20ml in my 700l ibc tank to get up to 2ppm.

Having finished cycling a couple of weeks ago and not yet added fish I can tell you that the bacteria don't die off when there's no ammonia/nitrite - they hang around waiting.

i'm using agg drain pipe, the same corrugated black pipe for my guards... i added an extra slits with a hacksaw between the corrugations.. not lots, and i find they allow pretty good flow

I like the plastic hardware netting. Roll it int a cylinder and zip tie it. That is how I am planing on doing media guards in the future.