Backyard Aquaponics
A place to discuss aquaponics

hi,

could someone please lead me to a thread or just explain (in very simple terms..) how the siphon works in a chift pist system...

i have been building small models to try to work it out, but i cant get the siphon not to empty the whole fish tank..

admitedly i am not draining it into anything but a bucket...

is there a valve or such at a water level that breaks the siphon action when it gets low enough??

thanks for any help!!

mate actually I am just as confused as you......would love this issue to be as clean cut

Ok here are a few pics of Earthbounds design ( ) I think the dranage is 7 or 8 mm ........it works

In a CHIFT PIST system you don't actually want to siphon the fish tank, what you really want is simply an overflow but one that draws water an solids from the bottom.

The Siphon normally goes at the drain of the grow bed if you are using siphons.

Here is a diagram that will hopefully help you.

Where you have the pump positioned...TCLynx ..mine is in the same place.....and solids dont flow freely to there....I end up with a build up of crap om the bottom ..

In that picture the pump is in the sump tank which (if it doesn't have fish) should have very little in the way of solids build up since the solids from the fish tank are being filtered by the grow bed before going to the sump tank.

This is really just a diagram since I don't have any systems set up quite like that.

I have noticed that rectangular tanks can tend to get solids build up in some areas especially if the pump intake or SLO is on one end and the fish don't tend to swim in a particular corner. Where the fish do swim the solids tend to get stirred up and sucked away. This is why many people like round tanks with the pump intake or SLO in the middle or conical bottom tanks with the fancy venturi drains or whatever kind of drains in the middle to take out the solids.

+1
siphons are for growbeds
Designs such as the T fitting at the top of the SLO or venturi are there to ensure the fish tank NEVER siphons.
Constant
Height
In
Fish
Tank

Pump
In
Sump
Tank

So constant height in the FT is what we're trying to achieve. we do this by having a variable height in GB <- well that's a given cos it's flood and drain, and adding a sump, where the water level changes, often drastically, with every flood cycle.
The pump is in the sump tank because of the less solids, and also so it doesn't chomp up your fish.
it is possible to have the GB and FT swap positions, and still achieve CHIFT PIST. (this is how I have my system set up) But the drain styles are all still the same.

Thanks for all the replies....


i do have trouble explaining what i am asking.... hehe.. reckon its a bloke thing

the venturi drain... this is what i was trying to understand and get to work...

i tried the t join at the top.. but thought the whole purpose was to suck the poo from the bottom of the tank into the grow bed.. in the models i made.. the suction appeared to be greater from the top..and wondered if there was a flap that worked like an epiglottis on the top..that would release when the water pressure was less..ie the water level dropped below the t piece.

but i havent been using it in a closed system... which i will soonish...

thanks

Hi aLH,

there shouldn't be any suction at the top - the top of the t should be high enough so that it is always out of the water. It's only there to let air in so that the drain doesn't siphon, plus to provide an emergency overflow in case the bottom drain gets clogged up.

haha..

sometimes i amaze myself at how dumb i can be!!!

when i made the small models.. i had put the t piece in with the straight part vertical...

even when i saw tlc's pikkie i still didnt see what i did wrong..

back to my cupboard...


thanks steem!!

i had put the t piece in with the straight part vertical...

not vertical.... horizontal...
arrrrrgggghhh

thanks all..

OMG!

im finally understanding!

Yep, you can have the fish tank and grow bed swap places but then you wind up with all your solids collecting in the sump tank and having to go though the pump to get to the grow bed. This is where some nasty stinky gunk can happen requiring cleaning regularly. So, if you want to arrange it that way, keep in mind how you will deal with solids or make sure the pump sucks them up.

Another option is to have a grow bed above the fish tank in addition to the one after the fish tank. Just make sure sizes are such that the sump won't run dry even if for some reason both sets of grow beds were to be flooded at the same time or make other backup arrangements.

Reading this thread there is a point that is confusing me. Can someone please clarify?
How does the flood and drain happens here? is there some kind of control valve at the pipe going from GB to Sump?

Thanks

from gb to sump is just gravity making it flow

pump in sump fills up the FT and it in turn fill the gb and it all runs again. just one pump in the cleaner water

i think getting the timing correct is what is going to give me the probs

but im guessing we regulate the gb draining by the amount of holes we drill in the gb drains?

timing (shudder)