Backyard Aquaponics
A place to discuss aquaponics

Hi,

I'm new in the aquaponics world and this forum seems to be the place to be for newbies having questions to figure out

My name is Baptiste and I'm from France, east from Paris. I live in a suboceanic climat, so temperature goes from 10/30°C in summer to -5/15°C in winter.
I still plan to make an outdoor system, as I think I can isolate the fish tank enough to avoid the water to freeze.

I already found a lot of info both in the website and the forum.

I am currently designing my system and collecting the different parts (blue barrels, cinderblocks, wooden palets...).

As I have no experience with fish or plants, I plan to start small with juste one 55gal barel as fish tank and another one cut in half for two grow beds. I plan to use two bell siphon in those grow beds.
The last barrel will be used as a sump tank under the two grow beds.

I have a few question to figure out :

How to calibrate the plumbing and figure out the numbers in order to have a proper cycle of water in the system?
I understood that the water pump in the sump tank should never get dry, but how can I assure that?

Thanks for reading and for all the informations available here!

Welcome to the forum Baptiste .



You could use an automatic top-up valve.

I think he means calculating out the volume of water in the growbeds so that he doesn't drain his sump.

Basically you need to figure out how much water it takes to fill your bed before it drains. If we use a 1m x 1m growbed as an example the math is easier.

If our hypothetical growbed is 30cm high, but the water only reaches 5cm from the top of the growbed and there is 3cm of water left in the bottom of the growbed (its hard to completely drain a growbed) then you have 22cm of water which works out to be 220L of space

The water is only in the gaps between the gravel or media. I work on there being about 60% media and 40% gaps but it is probably less. For our 220L from above that means that it takes about 88L to fill it.

Then you just need to make sure your pump is still submerged when all of your growbeds are full of water.

I've played with bell syphons. If you want to make it easy I suggest you use either timed flood and drain or just use constant flood.

Constant flood means that you don't even really need a sump, but you can still have one if you like.

If you put a weep hole in your standpipe when you make it, and find your bell syphons aren't working, just take them off and you have a constant flood system. Add a timer to your pump and you have a timed flood and drain system.

Have a play and see which works best for you :-)

That makes sense Sean .

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+1 to what Sean said about figuring the water volumes. You have to look at a couple of things -

1. If the power went out on your system, is there sufficient volume in the sump tank to hold all the water that will drain to it (volume in the beds and pipes).

2. Is their sufficient volume in the sump that it won't be pumped dry filling the beds before the siphon is triggered. On this one you have to look at a worst case scenario where all of the beds fill at the same time. Even if you try to get the beds timed so they aren't kicking off at the same time, they'll go in and out of sync.

You can use siphons for some beds and Constant Flood for others if your sump is a bit small. This also makes it so you don't have to top up quite as often.

Regarding the standpipe with the weep hole and other plumbing components within the grow bed - It's a good idea not to glue these so they can be removed and exchanged (say changing to a standpipe without a weep hole so you can run Constant Flood) or cleaned.

Hi,

I think you made a point by saying "have a play and see which works", and I will make a first try soon, then adapt to the results. I'll start as basic as possible and then try variants with siphon or timer.
I have to complete the amonia cycle anyway so...

I'll come back with some pics next time,

Thank you for those quick and precise answers.

Hi,

I'm still not sure on what way to process and I think I will try a system with one flood and drain growbed using a bell siphon, and one constant flood growbed.

I explained this to a french facebook group and few members told me that constant flood were for raft only and that if I used media, I had to use a flood a drain system, otherwise my plants are going to drown.

Considering that my first idea comes directly from here :



Could you confirm me that I can run a constant flood growbed filled with media? (clay pebbels in my case)
Is there anything different for constant flood that I should know before running that? (like oxygen level in water must by high?)

Thanks for reading.

PS: as promised, a picture of my system (still working on it, obv.) :