Backyard Aquaponics
A place to discuss aquaponics

Doing some adding on shortly, and have a quick question: Is the best method for distribution using a 3/4-1" PVC pipe with slits cut in bottom of pipe around the perimeter? Current method is single outlet in bed corner. Gluing pressure pipe and might as well make these better while I'm at it.

Don't glue any of the pipe inside the growbed, you'll need to take it apart and clean it.

As far as the design . If I was worried about even flow I'd just copy BYAP's design though.

After changing my media recently and seeing how the solids were basically right under the single point inlet,I have this time spread the inlet over a reasonably large area,I use 1 inch tube with slots spaced along its length,in my opinion around the perimeter is even better I'm sure this should help with the bed mineralising the solids.

I was wondering the other day why BYAPs design is round the outside. My reasoning was for ease of access more than anything and keeping the sides of the gb cool.

In terms of solids distribution in my mind the most effective place to have a ring would be 1/4 GB width/length in from each side, this way the solids can migrate in two directions.

I was thinking this with regard to AP wicking beds (AKA earthan beds). I'm not putting filtered water into mine so wanted to design to ensure the most even distribution of solids to avoid possible anaerobic areas. Access is not an issue as the dist pipes will be under the soil (ie no access!)

Never thought about the 1/4 GB idea...makes sense, but would be harder to plant? Also, possibly harder to remove/replant then on edges.

1/4 in is probably good.
I tend to think that the further away from corners (both actual corners and the edge) the less chance of flow into those corners.

I like the way we do it....

EB...just saw the video for the first time. duhh. drilled holed, or cut slits for bottom??

Drilled holes are my preference, I'm not sure why you would cut slits. You want the water to go straight down into your media without getting to the sunlight, best way to do that is with regular holes in a straight line down the pipe.

For our normal systems where we have the fish tank below and growbed higher, we tend to do 6mm holes about 15-20cm apart. For a chift pist style of system where gravity is doing the work, larger pipe size and 10mm holes to get as much unrestricted flow as possible.

Slits are less prone to clogging and they can still direct water straight down if they are longitudinal slits.

I assume you mean BIG slits, not just one cut with a grinder disk.... Need to make that clear...

define big....1/8"?, 3/16"?. 1/4"

I don't use em.....


I just find holes really simple.. We have systems here that have never had their irrigation pipes cleaned out.. Generally the only reason they get clogged is because of roots getting up into them from invasive plants, this will happen whether it's slits of holes.

Sorry. Given my desire for accuracy and precision (annal retentiveness/pedantry) I should have given more detail.

If the slit is incredibly narrow then it will clog really quickly. A long slit of x length but width d is less prone to clogging than multiple holes of equal cumulative area of diameter d.

This is really useful to know because often what governs the size of holes in spargers or manifolds is the desire for even distribution. Holes that have greater friction are easier to use to get even distribution. Narrow slits and small holes share this attribute whereas big holes don't. In AP since you can't use small holes because they will clog you can use (relatively) narrow slits instead.

Another approach is to use moderate sized holes which will clog overtime. Solids get deposited out of the first hole until it clogs, then the second, then the third, etc. Such a setup would need maintenance (cleaning of manifold once in a ?) but even though solids distribution would not be even at any point in time over an extended period of time it would be.