Backyard Aquaponics
A place to discuss aquaponics

Once the system (Flood and drain) has been running for a while (say 6 months) and the amount of nitrate is low, is there enough nutrient left for the last GB if I have a few connected in series?

Or should it be designed so each GB has its own input water fresh from the FT?

I get the feeling less than 100% of nutrient is taken from the water each time the GB floods and drains because most of the water doesn't get left behind to hang out with the beasties in the GB media.

Providing I have a healthy ratio of FT to GB, will it be ok to run the siphons into the next GB rather plumbing them each separately? Or will the first GB be greedy and take all the nutrient?

I want to be able to use a small pump as to get long life out of my battery backup because we get blackouts here that can last a while.

Connecting the beds in series would mean having to only fill one bed but still have it flood and drain 3 beds per hour.

-craig

I am not sure this answers your question (and perhaps someone else has better info) - but the way I plumb my beds is that the first bed gets poured into so if any bed gets the most nutrients then that would be it. From this beds bottom is a pipe that hooks up the bottoms of all the other grow beds with a T - so it isn't like they are in series of each other - just in series with the first bed. They all then fill up from the bottom, then drain out that same pipe through another growbed with a bell syphon. This way they also all get about the same amount of contact time with the water. I think it is ok to do it this way so long as the ST is big enough to handle all the water dumping at once.

only difference would be that the first growbed would have to handle 99% of the solids

So... are you talking stepped, cascading beds... with each siphoning to fill the other????

Think you'll run into all sorts of problems and difficulties trying to do it that way...

What is preventing you from merely plumbing all beds to fill/drain at once??

Just a point...
Eagle has his system flowing from a FT into the first GB, into the next , into the next, into the next and then into the sump
and another series of 4 the same...
He does have issues with the first of each GB getting the bulk of the solids and accasionally has to clean out the gunk.
But the system operates fine apart from that.
viewtopic.php?f=18&t=5504&start=0

Which certainly shows how the concept can be done...

And proves that nutrients, as in all other configurations... are distributed throughout the system...

I cascade in 2's. With different size gb's you can have a larger standpipe on the next gb as long as it is a smaller size. Mine are 500ltr to 380ltr. Some even flood & drain the bottom gb twice.

viewtopic.php?p=205652#p205652

Just to make it easier to see the success of the system

thanks people - I love how fast this forum is

monya "only difference would be that the first growbed would have to handle 99% of the solids"

mmm thats a good point. Perhaps i could get around that with a small gravel filter full of worms.
Are the solids a good thing to be distributed or something worth removing.

RupertofOZ "What is preventing you from merely plumbing all beds to fill/drain at once??"

Pump throughput, and the amount of water that would be removed from the FT. From what I've worked out I should be able to have around 1.5 GBs of water out of the FT at any one time even though I'd be running 3 GBs. I'm trying to avoid having to buy a sump. That would mean I could run a smaller pump, which in turn would mean my battery backup would stand a chance of running for the full length of a blackout. People up here insist on crashing their cars into my power link to the closest town
Money is tight and I already have the 100 AH battery and 7 stage charger. Id also like to keep the pump size down as I'd like to go solar.

thanks again folks

-craig

Is oxygenation due to the water creating a current in the FT or from running through the GB's?
Obviously both but there is a much greater surface area exposed to the air in the GB's rather than the FT (I would guess 100's of times greater) But then the FT current must be exposing a lot of different water to the air.

Anyone have any science on this?

-craig

Yep it will work last year i ran 2 systems both almost the same size one was stocked with fish the other wasnt and there was less than a 10% water change every hr
Both systems grew exactly the same

You could try a sequencing valve. I run one to 8 different gb's. 4 of thoses gb's cascade into a second gb.

Now THAT is Just. Plain. Sexy.