Backyard Aquaponics
A place to discuss aquaponics

Would this work?

And, the s-shaped pipe in the teal coloured circle, would this design work as well too? I need to make sure the drainage will drain out water fast enough so I was assuming a larger opening of the pipe inside the grow bed would guarantee that I'll never get an overflow in the growbed.

hey confuzedd...

there was a thread that talked of using a timer on the pump to fill the growbed... and a small diameter drainage pipe to empty it... this would empty the gb slowly while the pump was off...

but truthfully... if i can make a bell siphon anyone can...

Drain through the bottom... with an overflow standpipe... a straight section of pipe, with two holes drilled in the base...

When the pump is on, the small holes at the base of the standpipe will not be able to drain as fast as the inflow... water will rise to the top of the standpipe (your growbed flood level)... then overflow down the pipe...

When the timer turns the pump off... the water will drain over the standpipe ... until the level falls below the top of the standpipe... then it will continue to drain (slowly) through the two holes in the base of the standpipe until the growbed is emptied...

If your flood level is too high, you can merely shave the standpipe down... if the flood is too high because the inflow is overwealming the standpipe overflow... fit a ball valve (do it anyway) so that you can adjust the inflow...

About the bell siphoning thing, I was browsing threads about them needing touch-ups every couple of months. Since I'm a newb it would probably be like every 2 weeks So I was thinking of doing something even more simple by just having a drainage and having the pumps on a timer. I could have the drainage at the bottom, but I really don't want to elevate my grow bed off the floor. I'm trying to grow a small tree in my bed room, heh... so I'm being cheap with the space.

With Rupert's suggestion, like I said earlier I don't want to elevate my grow bed, if my design is really that inefficient, then I might consider changing the plans but I'm not sure why my idea wouldn't work too good? Because if it'll work just fine I'll keep the method as is, and/or I could put small holes on the pipes resembling Rupert's suggestion.

You could ... essentially the same idea... but your drawing indicates an exit point halfway up your growbed... thus, your growbed will never drain properly

You could sink something like a piece of 125 or 150mm PVC into the growbed and put the pump in there with a double level switch to turn it on and off.
Put the FT above the growbed with a slow drain 1/2 way up into the growbed. this will get the growbed onto the ground and get it right empty and the FT cant run dry
Or you could use separate elevated sump slowly draining into the FT and the FT brimming over into the growbed if you want to go CHIFT.
John

Ok I've rethink things. Rupert, which drawing did you mean; 1 or 2? Or are both incorrect? But either way, if either will work better than my previous setup, then I'll go for it.

Hey John, thanks for the suggestions, but I just don't like the idea of having the pump inside the grow bed. Seems more complicated too

No 1 is better as you need that external guard to prevent the media from blocking the holes in the standpipe...

But preferably, if your growbeds can be raised... or if there isn't too much incline... draining back into the top of the sump to oxygenate the water by falling into the sump...

One or two holes at the base of the standpipe is all that is required...

Like this...

The height of the inner standpipe determines the flood level in the growbed...

Here's a breakdown of the standpipe and reducer adaptor to fit the plug waste... showing the holes drilled through both components..

Nice. THanks for the pics, greatly appareciate.

I'm heading off to home depot in a few hours...

CF,

The way you have drawn things, your water level in the sump tank and growbed will be equal when the pump is not running. I have one system like that, but the growbed is about 60cm deep and the tank is about half that, so I assume I am only using the top half of my growbed and the bottom half is flooded, anaerobic, and useless (yes, I have my reasons...). Assume that anything that stays underwater 24/7 is useless and may even present a problem due to anaerobic decay. One huge advantage of AP flood/drain is that, while the roots get flooded often, they also get fresh air actively sucked down to them by the drain cycle.

I've placed my growbed (in two systems) on top of the sump for space saving and to lift it to a better height. As long as you have a bit of access for messing with the pump and growbed plumbing this works well.

Quick question. So will that little hole be enough to drain a larger GB that is 300 gallons?

Try two similar drains if you are worried that it might not be big enough. Our beds are half that size and use one drain, so a drain at each end of a big bed like that would work.

If the bed isn't draining fast enough and the pump is big enough to fill it to overflowing with no issues in the time allotted, then you can add another hole and test again. If it still needs to drain faster and the pump is still able to bring the flow up to the top of the stand pipe in the allotted time, you can add yet another hole.

I have a set up where the inflow to the bed is just way huge. I have lots and lots of holes in the bottoms of those stand pipes. It only takes me 10 minutes to get to the flowing over the top stage and then perhaps 15-20 minutes to drain.

And here is another diagram about stand pipes. You want the top of the stand pipe to be just about at the deepest flood level, that way when the water gets to about an inch below the gravel, it can flow down the stand pipe without causing issues in the bed. And you need a gravel guard around the stand pipe to hold the gravel away yet allow water in to drain down the stand pipe. It could be a mesh tubing or it could be a large PVC pipe that you drill lots and lots of holes or cut slits in to allow the water in but keep the gravel back. Then you can still look down around the stand pipe to make sure the drainage is still working properly.

I would recommend you lift the grow bed up between 4 and 8 inches. A couple concrete blocks would work well for this and though it might give you a little less space to work with, I don't think you want to leave the bottom half of your growbed continually flooded. Moringa don't like wet feet from what I've read.