Backyard Aquaponics
A place to discuss aquaponics

A guy called Morning Star Fisherman is selling an AP system with a clarifier and bio-filter placed before the GB. Would this not be self defeating? Not enough good stuff for the plants? He must believe in it to sell it. Is this a good idea? Here's a pic from his site....BTW... I cut this pic out of a .pdf file using a neat little piece of software called HANDY SNAP. You can still download it free here...http://www.321download.com/LastFreeware/page18.html. Lots of other good stuff there too for those who like this kind of thing.

I would appreciate feed back on this design....
Would it offer anything good to include in my design?

What media is in the GB. The size of the filters look small but the tank is not very large either. Only benefit I could see is keeping the FT clear. But running the water through a decent GB will have the same effect. Another down side is trying to clean out the 50g drums if something gets blocked up. And if they are full all the time allowing enough o2 for the bacteria to work. Maybe the guy didn't fully understand it before he tried selling it. I understand the learning process can put off the profit making part so sometimes it is skipped.

Yeah, is what I thought.
You want the plants to be cleaning the junk not you yourself out of a barrel. It seems to duplicate the bio-filter action of the GB.

He doesn't say what media he uses Duff. Here is the whole .pdf. http://www.morningstarfishermen.org/mis ... ponics.pdf
Has a range that he sells. Would some media do a more efficient job than others?

What exactly is a clarifier?

I think the clarifier is either a swirl filter or has sand of shade cloth to catch small particles. His pdf has no photos and all the drawings are not to scale.

Difficult to tell, re the variables. In that 'particular' setup no significant advantages I can see. Aside from the FT to GB ratio perhaps.
Duff
That sized biofilter depending on the filter media is quite capable of handling a significant fish biomass load, forget the 1to 1 or 1 to 2 ratio's of GB's.

A lot of people like to add bits of what they've seen in the UVI model and aquaculture systems.... IMO... because they just don't really understand the principles at work in flood and drain media based growbeds....

If it's a UV clarifier... then used for more than a day.... it'll kill, or severely inhibit your bacteria colony...

Most use it ... along with solids removers... to "polish" the water.... again IMO... because they just don't fully grasp the growbed concept....

The only other reason for external solids removers or bio-filters... are as pre-filters to NFT...

Or to try and elevate stocking densities....

I think I'll just go with plan A..... GBs as my filftration alone and fit my stocking rates accordingly.

Thanks guys.

I went to the Morning Star Fisherman web page to see if I could get more information. It is worth taking a look at. They are a non profit organization, trying to feed the hungry by teaching aquaponics, that has 110,000 gallons of tanks set up in Florida. It looks like most of their systems are RAFT and some NFT, hence the clarifier and biofilter.

Finn

They don't use media, so you need a clarifier and bio-filter.

Ok Now it makes sense, thought they were media filled beds

Their system is based on the UVI model. Since the UVI model is 100% DWC, all solids, including suspended solids, must be removed.
SRAC Publication No. 454- Recirculating Aquaculture Tank Production Systems: Aquaponics—Integrating Fish and
Plant Culture
Quote-
Effluent from the UVI rearing tanks is highly enriched with dissolved organic matter, which stimulates the growth of filamentous bacteria in the drain line, clarifier and screen tank.
The bacteria appear as translucent, gelatinous, light tan filaments. Tilapia consume the bacteria and control its growth in the drain line and clarifier, but bacteria do accumulate in the filter tanks. Without the filter tanks, the bacteria would overgrow plant roots. The bacteria do not appear to
be pathogenic, but they do interfere with the uptake of dissolved oxygen, water and nutrients, thereby affecting
plant growth. Unquote-

Yes. Makes sense now. Didn't even know it could be done this way. Learning... long way to go Think I like using grow media the best though. Seems easier to do. Better for the fish? What you think?

http://www.portablefarms.com/faq.htm has a similar setup. I see many advantages to this, and I think it would be better for the fish. The separate biofilter and settling tank would prevent ammonia spikes during harvest. The system is a lot lighter weight and more portable. The sludge from the settling tank is easily removed and could be added to the worm beds.

I don't really see a down side.

Or you can run a duel hydroponic system- run the water through gravel to trap the effluent, the water picks up oxygen because of it being a trickle filter and then run through a second hydroponic system- DWC, NFT, or strawberry towers, the water will be clean enough that you won't have to worry about clogging these systems. Then drain to a sump or in my case, the DWC is part of the sump and re-pump back to the fish tank.
This is do-able because what we require from the water are the chemical nutrients and they are mixed right into the water and these chemicals are being generated (mostly) right in the gravel. The balance needed is the production of nutrients to the needs of the plants, which must be maintained enough to benefit the fish. Believe me, fish can handle a great deal of nitrates so you have a huge safety net there; it's the plants that will suffer more if the nutrients are too much or too little but they will tell you-the leaves will turn yellow (too little) or the leaf tips will suddenly die (too much- fertilizer burn). Again, you have a wide range, especially if you stay with greens like lettuce.
The fish waste trapped in the gravel continues to decompose with aerobic heterotrophic bacteria (mineralization), which breaks it down into ammonia and CO2. The other two more familiar bacteria colonies (nitrosoma and nitrobacter) take it from there and the finished product is nitrates, which the plants will use both CO2 and nitrates. If your system is too loaded with effluent that you start to get anerobic spots, then you start to grow bacteria that is bad for your system (think methane biofilter)- your choices then are to clean the gravel or introduce worms to eat the excess. Gravel cleaning still might be a necessary evil eventually, with clogging fish waste and plant roots left behind, but if the system is balanced and maintained- it shouldn't ever come up.

+1, Badflash and Angie
excellent synthesis

Floating raft / DWC culture systems on average have a higher total water volume than growbed systems

fish density is rated at .5 pound/gal = 60 kg/m³
http://www.ca.uky.edu/wkrec/454fs.PDF

frank