CityRootsFarm wrote:
See I will have to go back out and re locate some info I had read to back what I an saying but from what I have read having a good three stage filter can help your water be more nutrient rich.
No, that is not correct. If you filter the solids from the water, then you're removing the substances which will break down (mineralise) to release trace elements and minerals into the water for the plants. If you capture the solids in a filter and do no more, the solids have the potential to break down anaerobically in the filters and produce all sorts of toxins and nasties which will kill your system. If you want to extract the goodness from the solids captured in your filtration, you need to remove the solids from the filters to a separate system (digester tank), provide lots of air for the aerobic decomposition and mineralisation of the waste material, then after a few days add the now nutrient-rich liquid back into the AP system; the remnants still contain a lot of nutrient and can be applied (with care) to a dirt garden.
If you want your water to be "more" nutrient rich ("more" is a relative term, more in relation to what?) then you're better off employing a filtration system which supports the mechanical capture of suspended solids and the mineralisation of those wastes in place in an aerobic manner, and which provides real-estate for colonisation by beneficial bacteria to process the ammonia and nitrites into the required nitrates; these filters are called growbeds. Worms can also be introduced to assist the mineralisation process, they also live in the filter media.
CityRootsFarm wrote:
By starting off with a swirl you can remove a large portion of the solid waste. Next having a mesh or " sponge" filter sifts the particles that are left to an even smaller size this filter also is starting the ammonia to nitrate conversion.
Again, no. The filters are not doing any ammonia conversion, except to say that the media in the filter will become colonised with beneficial bacteria which may do some ammonia processing, but the colonies will be disturbed every couple of days when you clean out the captured solids from the material to add to your digester.
If you're removing captured solids for subsequent processing then you have the opportunity to add some of the nutrient back into the system, but some of the nutrient will still go to "waste" as you spread it on a dirt garden or somewhere other than the AP system in which the solids were generated. If your third stage is a biofilter, then yes, ammonia processing can happen in there as this is not disturbed by the regular maintenance.
There is some good information around the place, here and elsewhere on the interweb about the mineralisation process, how it happens and the requirements for it to happen efficiently, including the ratio of surface area exposed to light and air to the quantity of feed given to fish.
CityRootsFarm wrote:
The last one will take the fine partials and catch them let the decompose and get even smaller and then work it's way into the system. Now if you take the swirl run off and use it with compost tea you can spray a bit at the base of your plant directly that way you lose little resources. Now again I am speaking theory here because I have yet to do, but from what I have read this seems to be a pretty good system for dwc nft.
If you're going to employ DWC/NFT then the water in which the plant roots are suspended need to be well oxygenated and clean of suspended solids which could accumulate on the roots and starve the plant. If you're removing all the solids and not processing them, you're removing vital nutrients and you will have to supplement your system with minerals and trace elements from another source (usually out of a bottle); or you can process the solids and return a good proportion of the nutrients removed back into the system (but as it's not 100% efficient, you might still have to supplement)
One of the many keys to success in an AP system is to only add good things to the system and only ever take the bad things out of the system. If you're adding badness or removing goodness, then you're system is less likely to be successful. The only good things we do remove are the harvests.
CityRootsFarm wrote:
Ok and question asked above if using nft channels and are going to use 2in pots what's a good size for the channel?
Forget where I got this titbit of information, but a basic starting rule of thumb is:-
for 2" (5cm) pots:
width => twice pot width, 4" (10cm), roots will grow out the side of the pots, so allow them some room, use tapered pots else the roots will impede the removal of the pots from the channel.
depth => aim for twice pot depth, roots will grow down from the bottom of the pot, depth will depend on the plants being grown and the voracity of the root growth.
space between pots => 3-4 times pot diameter, 6-8" (15-20cm), depending on the canopy of the produce and also the root length. (I'd aim for 20cm between pot centres, which will leave about 15cm between the edges of the pots)
Backyard Aquaponics
