Backyard Aquaponics
A place to discuss aquaponics

Looking into my choices for media, lots of information out there but my design is an unconventional constant flood, flowmedia style. If I were expecting to handle large solids large gravel would seem a logical choice since it does not clog easy but this system will be swirl filtered so I could take advantage of higher SSA (specific surface area) media since it will only be required to handle light suspended solids and ammonia/ammonium/nitrite loads. Ideally shooting for a 30min-1hr trunover (grow bed and fish tank) at moderate 10-15kg/m cu stocking density. An easy to work media would be nice seeing as a constant flood bed will most likely require a semi-annual cleaning but that is further down my requirements list. Must be Ph nutral seeing as I am aiming for a 6.0-6.4 Ph. Low cost would be nice seeing as I will end up needing several cu m.
Grow bed is to be submerged, covered constant flood, with tomato, cucumber, green beans, and bell pepper at the target crops. Only thing that has me worried is the aggressive root growth of tomato plants might cause dead spots in finer media in a CF system.

Might depend more on what is available to you locally perhaps..

Go you your local landscaper, take a handful of each back home. Test water only, then several of your products with the water, this will show you close to what your base PH will be (even though it will change as it matures)

As Joel says - see whats avail locally first

You like the flowmedia design? I am going with it because it is the only method that fit my efficiency based multi-stage design. Think of it as cascading flow media.

Sorry - for me its a design where you want to throw every type of idea possible into the 1 design with a pump that needs to be twice more powerful if done the other way cos you need to pump at differing heights

Done CHOP2 etc etc - argued the point, been there and done that

??? What is it about flow media that requires the extra head? Nothing in the design principals I have seen require any extra unless you are going flood and drain which is only 400mm or so. Seems more efficient to me especially if a multi-staged system is your objective since it can effectively run bio-filtration between fish tanks.

Whats your layout going to be inc heights?

CHOP2 required a larger pump, thats certain. With CF, its better

5 stage about 39" in head.

5 500gal tanks, five media beds, one 144 hole DWC tank and one small 800gph pump, should make for a really interesting project since I have never seen anything like it, as long as I can get enough oxygen to break down the ammonia and nitrites before the next stage it should be shockingly energy efficient. If not I can always add a small aerator at each stage, thought about going out to 7 stages but that might be pushing the envelope a bit in such a small system. I am looking for any little trick to keep breaking water surface tension the whole way down hence the submerged constant flood concept.

so you can turn the FT volume over in 1 hr? 800 gph - what about the head height? Is that at head or do you need to add that to it?

That flow rate is measured at 39" Yes all five tanks will be turned in less then an hour. Nitrate will increase stage by stage but they should still be a long way from dangerous levels when they reach the DWC tank.

With the DWC, you are prob aware but add filtration if straight from FT

Thats the good thing with Aquaponics, 1 system does not fit all

That's not what the "commercial" trainers say...

Point taken

But which trainer (lol) are you referring to?

No not straight from the fish tank, there is a media bed and fish mesh filter between each tank and hence between the final tank and DWC bed, don't need suspended solids making a mess of things.
This is certainly not a cookie cutter system and I would wager money that you won't see anything like this in AP text books, not well suited to a commercial application in it's current concept form, too much focus on energy efficiency to work in vertical integration, but much more efficient in terms of pumping then conventional single stage systems. Been working on this idea for about 18 months and not being able to build it yet is driving me nuts.