Backyard Aquaponics
A place to discuss aquaponics

I am just wanting to work out my growbed cycle rates

and would like to know what peoples thoughts are on Flood / Drain times

I have seen users Flood and Drain @ 1:1, 3:1, 1:3, 4:1, 1:4 ratio's

my grow beds will have worms in them and will not be cycling water back into the FT
it will be topped up with fresh rain water

Flooding into growbed will be gravity Fed from RFF and from NFT sump with taps to adjust mixed flow rate
Draining from the growbed will be dumped into sump then pumped back into NFT grow area's
(micro filtered water)
as these grow beds will be decoupled from FT they will be mostly processing solids caught by the RFF that have passed through mineralization tank

The idea is to have water trickling from bottom of the RFF directly to mineralization tank
( still need to work out the retention time ) then into grow beds for worms and plants to do their thing

I am using this method for 2x reasons
#1 the use of other fertilizers will not affect FT
#2 trying to lower electricity usage because this method will be for low flow rates

I will be using high flow low head pumps for filtering bulk of the 90kl FT water passing through an moving bed media filtration system to keep the water cycling every hr with the bulk of solids quickly removed

but stuffed if I can work out how to get all that good nitrates the moving bed bio filters have processed
from the FT water to the grow beds .. de-coupled
maybe I should just run some DWC / FRC coupled ?

I guess while I am at it what % of grow bed should be statically flooded / drained
ie)
how many mm from bottom should stay flooded
how many mm from top should stay drained

I am still deciding if I should use multiple grow beds ( IBC ) or just make 1 huge ass growbed
at least then I could have the drain away from my bedroom window
tho I guess I could lead all the dump pipes into a sump down the other end

viewtopic.php?f=1&t=6547&hilit=flood+times
viewtopic.php?f=1&t=6651&hilit=flood+times

..
Whilst I am.easily confused, you have achieved it easily..

You are asking about timed flood and drain and then paint a picture of constant flow from RFF and NFT..

How does this work timed..

It could be better to have one thread and expand, rather that expect folk to go chasing other info in other threads..

Confusion... I think you are saying that you are going for a divided system of RAS and Hydroponics, like my second system..

So if you are to collect solids, then surely the RFF will be in the fish tank loop

PS.. I suspect that you won't be able to trickle from the RFF..
I find that you have to have a serious flush, to get muck to move
..
.

YEs I'm a little confused as well... I would vote for multiple smaller beds rather than one huge bed, easier for water to flow a short distance through media, especially when root mass grows. Also allows you to disable one bed if required or remove invasive plant from one small bed rather than huge bed..

mostly the flood and drain is about achieving some desired/required balance to suit the AP system.
Particularly as the media is the fish tank filter.

eg. getting enough splash to aerate, enough volume and movement through bed to bio-filter
needing/wanting to run a pump continuously or not.

keeping the plants wet and frequent turnover for 'new' nutrients is actually the least important. BYAP trials and everyones different system here on the forum shows that. You can run a system with one flood/drain every hour or even longer if it was just about the plants provided sufficient water was retained in the GB to keep the media and roots moist. And plants don't suck nutrients out at great rates (rates of per day rather than per minute). You can have a bato bucket and top it up once a day provided it has a decent air gap.

a slow drain will tend to leave solids in the GB simply because there is not enough velocity to draw solids through the media to the outlet.

I'm voting for one big grow bed. I built a huge one, and it works fantastically. Takes longer to fill and drain, but I'm happy with that. But I wouldn't be putting something like Mint or Celery into it.

The timing of the flood and drain doesn't matter, as long as the water is being turned over once per hour.

Make sure you post pictures of the build as it comes together.

these are the two aspects that seem to be the main issue.

A lot of water passes through a fish tank and grow bed system, so that is a lot of water to be replaced every cycle / hour etc. The whole purpose of recirculating systems is to address this primary issue of continuous large replacement water volumes.

how does the disposal water cease to be - the common option in a circulating system is to go from media GB to a DWC. So this addresses the 'new nitrates from bio-filter'. But in this system what happens after that as the NFT will not require significant volumes ?

-----------------------------

*IF* you were to go down this path then really you need to basically consider a water balance (volume) and nutrient balance (load). Presume aeration can occur at any /every stage.

thus the first question is - how often and what volume does the fish tank water need to be replaced, and how do you filter in between this demand. The second is how many beds can you effectively pass water through to optimally use and reduce the nutrient load. That may even involve your 'sump' basically being a storage between stages or the recirculation point. Then basically what do you do with the water at that point.

Your system must be able to dispose of water at the same rate that it add's it in.

WATER

I am more of less talking about growbeds and the bell siphon

just sussing out the flow rate I should make it for my 90kl setup
( gravity feed trickle from RFF waste + gravity feed from bio filter with tap's for tuning)

as once the bell siphon is made that's it no more tuning of the drain rate

I am actually not flowing all the tank water through the gardens

especially the grow beds they are only 36sqm / 10 000 L ( 20 000L sump )
that would mean flooding them and draining like every 3 min @ 1:1 for the 1hr cycle

The tanks will be gravity feeding up to 1800LPM to the bio filter / grow beds ,
I will have pumps moving water directly back to the tanks from the bio filter
to keep water cycle rate high ~ 1500lpm ( half to grow beds half back to tanks )
plus another high head pump pushing micro filtered water from bio filter to the NFT loop @ 200 Lpm ( 800sqm garden)

that should give me around 10~15min cycles


now from what I can work out for 1 foot deep grow bed ( sorry if my math is wrong )
90 mm bell siphon should discharge 7500 lpm down to around 1000 lpm
2" 50mm bell siphon should discharge 1600 lpm down to around 250 lpm

I think the bell siphon rule was double input = 4x drain flow = 1:4 ratio ?

*edit* and I gave up on decoupling growbeds and moved tank location to bottom of hill ,
still sussing out the NFT options as I will be mixing fertilizers ,
possibly top NFT tank from FT
or
let their water flow into growbeds then back into FT

the fertilizer will only be aeroponically added so hopefully not much leaches into the water anyhow

I have 8 IBC grow beds and one 150 gal. raft system and I'll run my pump for 15 minutes and the pump will not run for 1 hour and then run for 15 minutes. This operates 24-7 and all my plants are growing and healthy. I think the gold fish are happy.

Question for the Administrator: How can I add pictures to my page?

Thank you for all the help and info this site provides.

(a). In the "Quick Reply" section immediately below the last post, click the "Full Editor" button.

(b). In the "Upload attachment" section, click the "Browse" button. It should open your "My Pictures" folder, or similar, wherever you store your pics on your PC.

(c). Select the picture you want to upload by double clicking it (max pic size of 800 x 600 is recommended). The picture details should show in the field next to the Browse button you clicked.

(d). Click the "Add the file" button.

(e). When you've finished your text and uploading pics, click the "Preview" button to see how it all looks, if all good, click "Submit"

I think every one has his/her own experience. There is no hard and fast rule to make a fix criteria in this regard!