8x15 greenhouse build

[Fishy McFisherson]

Hi folks, here are some photos of the progress of our greenhouse build. We went with 8x15 because anything over 120sq' requires a permit within Sacramento city limits, and we wanted to keep our first foray into aquaponics relatively small.

So far We have the 4x4 "foundation" square and level, roughly 50% of the excess dirt from within the foundation has been removed, and when not digging I've been working on stands/cradles for the growing beds.

Once all the earth moving is complete, we'll tamp it down, lay down some weed barrier. and pack the inside of the foundation box with gravel.

[Fishy McFisherson]

The individual stands will be tied together with a fence board running horizontally at the base of the center cradle, angle iron across the top rails to keep the sides of the grow beds from flexing outward, and more angle iron connecting the frames through the middle to support the belly of  the grow beds.

[TCLynx]

Are you planning on using that galvanized stock tank as a fish tank or sump tank?  If so, please make sure to line it or coat it with some fish safe coating.  The galvanized coating contains zinc that will leach into a recirculating aquaponics system and is likely to become toxic to fish especially as the pH falls.

[Fishy McFisherson]

The stock tanks are going to be my fish tanks. I have another thread on the coating subject.

 

http://aquaponicscommunity.com/forum/topics/liquid-tank-coatings
 
TCLynx said:

Are you planning on using that galvanized stock tank as a fish tank or sump tank?  If so, please make sure to line it or coat it with some fish safe coating.  The galvanized coating contains zinc that will leach into a recirculating aquaponics system and is likely to become toxic to fish especially as the pH falls.

[Fishy McFisherson]

I got the first stand 99% assembled and filled with water. VERY stable. Gave them a good shove from every angle. Doesn't look like the angle iron along the top rails will be needed, but they're not hurting either so i'll keep it in the design for the second one. Progress! WOO!

 

[Paul Trudeau]

looking good Fishy!

[Fishy McFisherson]

Thanks Paul. My plan is to get the filtration up and running on the one tank, plumbing the water lines going to the grow beds and the drain back to the tank in such a way that I am able to add the second tank like this one and additional grow beds as they are completed* (*to be read: as funds are available). The current filter plan is a swirl filter for solids separation, possibly a secondary fine solids filter, and a fluidized sand filter for bio-filtration, so that the only thing going into my beds is nutrient rich water. Might be overkill, but when has too much filter ever been an issue?

 
Paul Trudeau said:

looking good Fishy!

[Paul Trudeau]

Some say its better to keep all those solids in the system, where the minerals etc contained within can be released to be utilized by the plants.  I'm not sure myself.  I'm sure what you're doing will work well...

Fishy McFisherson said:

Thanks Paul. My plan is to get the filtration up and running on the one tank, plumbing the water lines going to the grow beds and the drain back to the tank in such a way that I am able to add the second tank like this one and additional grow beds as they are completed* (*to be read: as funds are available). The current filter plan is a swirl filter for solids separation, possibly a secondary fine solids filter, and a fluidized sand filter for bio-filtration, so that the only thing going into my beds is nutrient rich water. Might be overkill, but when has too much filter ever been an issue?

 
Paul Trudeau said:

looking good Fishy!

[TCLynx]

If you are planning on very heavy fish loads and you don't like veggies, then perhaps the extra filtration and solids removal will be appropriate.  I personally don't like the added maintenance of cleaning filters all the time so I've learned to eat more veggies.

[Fishy McFisherson]

Very good point, I'll have to run it by the design review board (girlfriend).

 

[TCLynx]

If you have the space for swirl filters and other filters, you probably have the space for some sump tank and extra grow beds instead.  If you can manage a 2:1 grow bed to fish tank ratio then you will likely not need supplemental solids filtration unless you really push the stocking densities to the max and don't wash your media and go sprinkling rock dust into the beds.

[Fishy McFisherson]

thinking of doing a slow moving shallow tank below the other grow beds to act as a sump/duckweed pond/crayfish/freshwater prawn tank. Anone have thoughts on this?

 

[Paul Trudeau]

crawdads I've kept have always eaten any vegetation that was in the tank.  that said, haven't tried them with duckweed...I'm sure others have more experience than me to rely on.

Fishy McFisherson said:

thinking of doing a slow moving shallow tank below the other grow beds to act as a sump/duckweed pond/crayfish/freshwater prawn tank. Anone have thoughts on this?