Backyard Aquaponics
A place to discuss aquaponics

howdy!

More foolish noob questions i am afraid. I designed and bought most of the parts for my first small window system , before i learned about 'flood and drain'.
I have a 48L glass tank and which will have an 18L media bed above it. I cannot see myself being able to have a sump on the system because having an overflow from the tank will require me cutting a whole in the glass, I just cant see that going well.
I thought the using flood and drain but on such a small tank, to fill the media bed a third of is size will make the water level fluctuate far too much.
So my thought is to bury some small bore rubber hose riddled with pin holes, coil it all over the media on continuous flow and hope for the best.
All the info i have seen on continuous flow seems to have lots of water, sloped beds and floating root systems.
Will this work or is their some wizened ingenious way round this problem, like 'don't spend all your money on a glass aquarium tank before you have thought it through properly!'

cheers

flash

continuous should be fine with GB over FT and pump in FT. You would then only need holes in the GB.
(no holes in glass required). [ Basically a mini IBC of Aquaponics set up ]

set up as a constant flood and perhaps put a small ball valve low in the GB so that every now and then you can stop pump and drain GB into a bucket or something. That would deal with dead water in GB and also allow you to add clean water to FT as required (else just add slowly back in to FT).

I would use PVC pipe on GB surface rather than rubber pipe for the distribution as holes tend to block less.


one trick with continuous flow is to actually have the GB standpipe intake via pipe at the bottom of GB.
You can do this just like a siphon but simply have the top open to air. That way water feeding the overflow is coming from bottom of GB.

lettuces etc should go fine in Constant Flood. (see other threads on this)

@flash_shabby,

Hi, you can take a look at my system linked at my signature, you are probably in the green with some minor modification to your GB. Hopefully you have enough space in your GB for a stand pipe, it makes determining the water level in your GB so much easier. Pump from FT to GB and let it drain continuously.

@dlf_perth

You brought up an interesting concept where the input pipe coming from the bottom, thanks for sharing. Can you please give a fast comparison to the benefit of having it this way compared to when the input is from the top?

Regards

the usual negative for continuous flood is that dead zones can occur because water always travels the same path.
And if you feed from the top and drain from the top the bottom does not circulate as much.

so ideally you want a system that puts new water in at the top and takes old water from the bottom.
This is what a siphon achieves - in the same way many SLO are setup for the fish tank.

You can do it various ways - one option is shown here for an out of side overflow.
viewtopic.php?f=18&t=23874 see last slide.

or use a bell siphon type approach (just leave pipe open at top)

or use something like this... (b) is better because it can drain a larger area), but (a) is easier to maintain.
Dont glue anything, and in your case just drop vertical to fish tank.

Using Constant Flood, provided you don't overstock, you can run for a long, long time (years) before you have to do any cleaning and the dead zones and flow channeling usually aren't a problem. Growing tomatoes in any of the systems you'll have roots that cause this so it isn't unique to CF. Without distribution of the incoming flow you will get a buildup near the inflow but nothing to get real concerned about. Check out the BYAP trials thread for a side by side comparison of growth in three different types of systems.