Backyard Aquaponics
A place to discuss aquaponics

I have dug an octagonal grow bed, laying liner, plumping, and media are to be done, will get a picture tomorrow.

Dimensions are,
Shape = octagonal
Length of outer side = 5 ft
Length of inner side = 2 ft
Width = 3 ft
Depth = 1 ft
Volume = approx. 550 gallons

We are looking for some expert ideas on plumping, flow rate, make partitions or to keep it as one, CF/FD, media, etc.

Pump - it is a one pump system, 4000L/Hr. Plumping extension is possible from an existing gravel grow bed or NFT channel. We don't have the budget to add another pump at this juncture.

For media, I have gravel 1/2 inch size, M-sand, and River sand. Is that okay if we add all these together and use in this?

Also it would be great if you tell us what all plants we could grow in here.

Appreciate all your inputs.

How would you prevent the sand from intermixing with the other media...

Let me try thinking out loud with you... no decisions made yet.

Some sort of gravel mesh at the bottom, say 4 inches and top it with 8 inches of M-sand/river sand combination media plus earthworms. Sand would go down a bit but not all of them or we would need to look at some sort of divider to prevent it. There is external solids' filter that is cleaned at regular intervals.

You can actually lay relatively fine gravel/sand on top of coarse without it mixing during the flood and drain cycle because the water velocities are so low during the drain cycle.

You are more likely to have problems with sand mixing with lower coarse gravel as a result of disturbance during planting and harvesting.

could you use something like a geotextile fabric to seperate the two?

I haven't needed to.

Great question. We have plenty of cut pieces lying around that can be used. Cover the gravel entirely and keep some 1/2 inch holes? Will this work?

Thanks Stuart. Noted the points. Water velocity is going to be pretty low as I am thinking of expanding the plumping of one of the NFT corners. Change the L to T, extend the pipe, and to have a fish bone distribution channel inside the bed. How about this one?

Here are 3 pictures - front, side, and back views of the grow bed.

And here is another rectangular grow bed pits being dug up.

How are you draining your GB's?

are you going to dig a trench and a sump or do you have a lower level area for the ST / FT?

Hi slow, we do not have a sump tank... it is all one big fish pond. These grow beds are raised above the ground well enough to be drained directly to the FP.

Do you have snails and pest in india?
Might want to consider some form of shade house or protection around the outside

Hi Jay, there are no snails.. we are lucky. Pests, yes there are some similar to the ones in non-AP plants.
It is all open now but thinking of some shade cloth for the plants. It is too much sun out there these days.

Here is a wicking bed diagram we think of executing in the new bed.
Opinions please. Would it wick up to 8 inches? Instead of an overflow pipe, has anyone tried an adjustable standpipe? Anything else?