My hybrid horizontal NFT system design, a work in progress

[Averan]

http://sketchup.google.com/3dwarehouse/details?mid=af9fe4b40ff5f128...

I don't yet have the plumbing linked up, but seeing as how I've spent so much time already putting this together I thought I should go ahead and share it.

It is a modified CHOP2 system with a yin-yang flood&drain IBC media bed and media-filled sump for solids break down passing to 2 aerated swirl filters before going into the NFT pipes and the IBC fish tank.

[Sahib Punjabi]

Nice...:-)

[Averan]

Thanks.

With your NFT pipes, are you running the water level at about half-way (2" deep, w/ outlets centered on the ends)?

Are you using hydroton as the medium inside net pots?

I've been experimenting with a smaller volume of water running inside the pipe by positioning the outlet at the bottom of the end cap instead of the center, as well as using a wicking plastic fiber instead of hydroton for the medium.  The poly fiber acts as a very effective solids filter!  I've already started to notice a nutrient gradient along one 15ft section of pipe despite other similar setups where people have claimed an even distribution.  I'm trying to avoid this issue in my new system design by adding the 2 aerated swirl filters to trap solids and further digest them into dissolved nutrients.

[Bob Segraves-Collis]

It is and impressive design, compact and tidy.  From the drawing I presume you will have multiple (I count 3) pumps as the troughs are below the water level in the fish tank and the drain level of the fish tank is below the grow bed.  You might consider a small rearrangement - put the fish tank in between the swirl filters and the troughs and extend the troughs above the fish tank and the swirl filters.  This would allow for a gravity feed from the troughs to the fish tank eliminating on pump.  It would also maximize the sun exposure of the plants.  The plumbing would be less complex as well.  If you have the real estate to play with, consider having the fish tank higher so that everything flows from there via gravity ending at a clean water sump and pump from there to the fish tank.  The clean water sump would allow for adding O2 if you need to as well as balancing the PH for the fish. This would call for a timed drain valve in the fish tank, that might be a issue if you are not operating on mains power.

Averan said:

Thanks.

With your NFT pipes, are you running the water level at about half-way (2" deep, w/ outlets centered on the ends)?

Are you using hydroton as the medium inside net pots?

I've been experimenting with a smaller volume of water running inside the pipe by positioning the outlet at the bottom of the end cap instead of the center, as well as using a wicking plastic fiber instead of hydroton for the medium.  The poly fiber acts as a very effective solids filter!  I've already started to notice a nutrient gradient along one 15ft section of pipe despite other similar setups where people have claimed an even distribution.  I'm trying to avoid this issue in my new system design by adding the 2 aerated swirl filters to trap solids and further digest them into dissolved nutrients.

[Averan]

1 pump.  The plumbing itself is pretty simple, but modeling it in 3D is tiresome.  ;)

The fish tank level only needs to be a few inches higher than the upper media bed for gravity to work its magic (solids lifting overflow).

The big flaw with the current state of this system is that I have two NFT pipes located higher than the outlets on the swirl filter barrels.  I'd rather not have to raise those barrels any higher, otherwise I'll have to ditch the cinder block/wood palette design and build a sturdier frame.  If you take out the swirl filter barrels, the single pump in the sump can easily push the water up into the top NFT pipes.

I don't like heavy containers of water lifted high into the air.  This is especially dangerous and materials-intensive in earthquake-prone areas such as California....and even more so when you consider installing a system on a hillside!  Having your fish tank on the ground helps insulate a little as well as making it easier to get to your fish.

By keeping the fish and media components low to the ground I had intended to either extend some of the NFT overhead or install solar panels for an off-the-grid system.  I'm envisioning a small greenhouse tent covering the upper media bed to create a nursery for seedlings.

The upper bed is filled from the fish tank and drains via siphon to the lower sump.  The sump, unlike most sumps, is also a media bed, but with a media guard protecting the pump.  The sump blends up whatever solids made it past the worms and media and pushes it up into the aerated swirl filter barrels.  The swirl filters will have yet more media inside and be heavily aerated to supercharge aerobic digestion of the remaining fish waste.  The collected solids can be drained out the bottom back into the worm-filled sump for another go-around.  From the swirl filters the water would overflow out into the NFT module as well as into the fish tank.  I'd like to have the option of turning off water circulation to the NFT modules at night while maintaining flow through the fish tank.

I'm still playing around with the swirl filters...they are a recent addition in my attempt to maximize the digestion of fish waste in the least amount of space.  I am trying to avoid having to deal with thousands of pounds of heavy gravel and want a design that can be installed on uneven terrain or slopes.

[Sahib Punjabi]

Namaste Averan,

You are correct to state that I am running the water level at about half-way. I have used  Hydroton, Rockwool as well as Coir Mix and am now slowly switching to Horticubes. You experiment should work. Another item you may want to consider is to add a net sleeve (like a stocking), at the entrance so as to catch all the undissolved and large fish waste / nutrients. 

I going to start to limit my use of NFT's to otherwise unusable space and go with other vertical growing options...I will share soon after my Workshop scheduled for Dec 10th & 11th.

 

God bless,

Averan said:

Thanks.

With your NFT pipes, are you running the water level at about half-way (2" deep, w/ outlets centered on the ends)?

Are you using hydroton as the medium inside net pots?

I've been experimenting with a smaller volume of water running inside the pipe by positioning the outlet at the bottom of the end cap instead of the center, as well as using a wicking plastic fiber instead of hydroton for the medium.  The poly fiber acts as a very effective solids filter!  I've already started to notice a nutrient gradient along one 15ft section of pipe despite other similar setups where people have claimed an even distribution.  I'm trying to avoid this issue in my new system design by adding the 2 aerated swirl filters to trap solids and further digest them into dissolved nutrients.

[Averan]

Sahib,

What are your reasons for switching over to vertical pipes?

[Sahib Punjabi]

Significant increase in growing space and better water / nutrient control. More info after Workshop plus photos :-)

 

God bless,

Averan said:

Sahib,

What are your reasons for switching over to vertical pipes?

[Averan]

Here's a conceptual mockup for the blue barrel bio-digesters combining a typical swirl filter with my own design for a fluidized hydroton aerobic digester:

thoughts?  comments?  ideas?

air is pumped into the first barrel via a circular diffuser that blows a ring of bubbles up the outside to create a circular vertical flow.  the goal is to break up and digest any solids that have made it this far into the smallest pieces possible.

then the water/solids move on via an SLO to the swirl filter for final polishing and settling.  both barrels have bottom valves in case any solids collect and need to be occasionally drained out (back into the sump for another go-around?).

[Izzy]

What is a CHOP2 system?  What is a yin-yang F&D IBC media bed?

You are very creative! :-)

[Averan]

CHOP2 = constant height one pump...2.  means fish tank overflows into sump.  pump in sump goes to media beds as well as back into the fish tank.  think figure 8 circulating loop.

yin-yang media bed-sump is my own invention.  basically, why waste all the volume in a sump with just water?  might as well fill it with gravel and worms for extra solids digestion.  :D  the yin-yang part comes from how the bulk of water oscillates between the Flood & Drain (F&D - siphon) media bed and the media-filled sump below, effectively giving you 2 flood & drain beds but using only one siphon.