Backyard Aquaponics
A place to discuss aquaponics

Joel
You may know this already but in your book you discuss problem you had regulating water flow.

Well living in a island with a 2000yr old irrigations system you pick up a few things. How the Balinese control the even distributions of water even in piped water systems is they build a tank sectioned off into inlet and outlet and exposed to the atmosphere.

If you wanted 5 outlets you would have 6 sections. To control the flow you then the lower a portion of the edge between each edge outlet and the inlet so that water filling the inlet will over flow into each outlet in proportion to the size of the hole you cut. These rectangular have to be level with each other.
The individual growout beds then can be any level and they won’t siphon more water.

I have a quick graphic I made up if anyone is intereseted

I would love to see the graphic - please email it to me or get Earthbound to put it up on the forum.. Regards Murray murray@boatshop.com.au

Interesting idea Matt, makes perfect sense......

Ok the rear is inlet the front outlets obviously the capacity of the outlet needs to be greater than the inlet and and elevated above the system.

Any other questions feel free to ask.
Matt

I think I get how this system works. The only time it would stop being effective is if you let the flow get away from you and one outlet tank actually filled (due to the outflow being slower than others) while the others were draining more quickly into the beds. This would be avaoided by the fact that you would only be pumping a set amount of water into the inlet tank each time - before then letting the outlet tanks empty fully - using it for a flood and drain system. This system would also be good to allow you to use a high capacity pump which you would then only have to operate less often because of time taken for the water to flow out of the outlet tanks into the beds. This unit would have to be sufficiently higher than the beds to allow for a reasonable gravity feed pressure to ensure that water is feeding all of the grow-bed grid sufficiently. I wonder how much higher it would need to be to obtain the required pressure?

My 1 other question is:

- Does the water in the inlet tank - lower than the cutouts to the outlet tanks - just stay there between pumping cycles. Does this encourage algae growth etc?

This is good info matt - in fact may help me with something else I have been thinking of for my system design hmmmm

Ok – when I saw this system it was being used to supply water to houses below the source. The rectangular holes were of different lengths controlling how much flow went to different locations like little waterfalls ie the outlet box's shouldn't fill up as the outlet pipes should of sufficient capacity.
The hole heights have to remain the same level. This system is actually quite small like 30 - 40cm square.
I had assumed that the volume of water required for each grow out bed was the same. If one required more to one bed you just made that hole longer in proportion to the amount required.
Now from my understanding of the aquaponics system when one bed is full the excess water flows into the drain system without restriction. The danger in this system would be loss of water due to the pump supplying to quickly for the outlets to handle resulting in overflow. I suppose this could occur if roots entered the pipe delivery system at the grow beds.
A solution would be to have an overflow system eg a large diameter pipe outlet located well above the standard outlets returning water to your tank. Or locate just locate box above your tank.


“Does the water in the inlet tank - lower than the cutouts to the outlet tanks - just stay there between pumping cycles.â€

Matt - good to hear the the unit is so small - makes it much more feasable to build/use. I may have missed why this topic started, so just want to identify the benefits of using a unit like this. I was thinking of several which I started to type but then discounted in favour of other methods. I am not being sarcastic here, the unit has some attraction to me, I am just not getting its benefits at this point.

When I read the Backyard Aquaponics Joel mentioned he had problems when adjusting the flow to different grow beds. When he adjusted one bed it then effected the others. I believe although I have not tested this that this may solve this problem at least in part.

Yep dead right Matt, it can be very difficult to adjust the flows into seperate beds.. In my new system I will have one section for the yabbie duckweed production, this will require one pipe feeding into 6 seperate half barrels and I was wondering how I would do it.

I think that a box like this could be the answer to my problems, rather than having multiple small taps on every bed. The only way I might change it is to use 'V' notches instead of square notched in the internal wall.. Now to figure out some simple materials to construct it from.

Hi Joel

The rectangles allow you to calculate the flow to each outlet easier.

ie if 1 of 3 rectangular holes was twice as long as they other 2 The largest hole is equal in length to the other 2 flow thru it would be double. If this is not an issue V's should work fine.
If any one tries this before I get to it let me know if you have any problems.

I wonder if there would be a problem with build up of solids in this setup. Unless al the solids are constantly in suspension, wouldn't you get build up in the first section?

Cheers,

Donarto.

Good thought Donarto, there probably would be a build up of solids in the first chamber. If this was set up as a box, as per the diagram, it might be an idea to put a valve in the bottom side of the first section, so now and then a quick opening of the valve would release any solids build up... Good for putting in the garden...

Yeah - the first section would act like a settling tank. A sloping bottom to that drain valve would concentrate the solids to one area too. I might also put my initial inlet lower down the back wall, or even in from the side instead of the back, so that the force of the flow didn't force more water over the overflow directly infront of it creating uneven distribution of water flow between the overflows (of course I don't know how strong the pump is... this may not be an issue).