Backyard Aquaponics
A place to discuss aquaponics

An interesting tweak on a standard CHIFT PIST system. It would mean that you would have to have a Top Tank large enough to carry ALL the water needs of the top GB throughout the 24 hours…. not impossible……and I would use a Sump at the bottom rather than the Fish Pond….

The TOP TANK water is then filled once in 24 hours…. need a strong and rapid pump - or strong pedal power! - if a big system….. and over 24 hours it leaks into the first GB - time and again -until emptied…. A flout kicks in for rapid exiting of GB water to draw oxygen into the system… and give enough time for the plants before the slow leaking from above tops it up again. Only the top GB would be filled like this if built in series..... so more water hungry plants perhaps put here cos always filling.

If done in series…. more than one set of GBs to FTs…. then normal CHIFT PIST continues down the hill…. or gradient created… It would only be the first GB that would be slow in filling because CHIFT PIST would ensure that a Fish Tank would exit water normally through the SLO (Solids Removing Overflow) to the next GB in series… on down. Then the cycle would wait until the trickle fed top GB is filled again and the cycle would repeat itself.

Everything ends up in the Sump… so Sump must be as large as Top Tank because pumping only begins again when Top Tank is dry….. hopefully tweaked so that that takes 24 hours.

With only one pumping a day it can be the early morning exercise to pedal power the water all back up to the top! ..... very early morning if a hot summer! Can't believe how hot it is now... and only Spring.

Top Tank and Sump are going to have to be big enough to carry enough water for all the AP cycles required for a 24 hour period….. that is the possible drawback…. But I do admit to loving the concept. It is basically stored energy up top where you need it. Frank should just love that! No vulnerability to power cuts…. Only one time of the day needed for power and anyone could pedal for an hour a day! Always hoping it is only one hour a day … of course!

It could also be designed to work over 12 hours to bring Top Tank and Sump tank sizes down to half. If the system was not cycling at night.... in winter say.... to keep heat banked instead of dissipated with cold night air in GBs.....this would be good. Summer might need cycling to bring temps down of course.

A very interesting idea!

Excellent analysis, Chelle
indeed I lllove it

and your analysis of Feinstar's system possibilities is almost perfect too

except on one detail:
sump must not be as big as the top tank
sump can even be rather small as it must at maximum only be able to contain your batch volume
(batch volume as opposed to day volume or 12 hr volume or, for that matter, 1 hour volume, depending on how often you want to exercise )
it could even be smaller than your individual fish tanks
but I would advise never smaller than the water contents of one set of growbeds lest it should overflow.

Top tank can be as big as you want and can hold fishes
as long as it is a VHMHIFT (Variable Height Minimal Height In Fish Tank) tank
which in fact every CHIFT tank that can hold some extra volume is, unless it is equipped with an overflow at the Constant Height level
and as long as the volume of the tank above the Constant Height level allows for topping up the tank with your batch volume
I guess that would make it a MH+BHIFT (Minimal Height + Batch Height In Fish Tank) tank
If your top tank surface is large, that would mean only small level fluctuations

So, in this setup, you can pump up your batch volume to "top up" the top tank at regular intervals
and with adjusting of the solids lifting overflow drain output flow, try to spread draining as much as possible over the chosen time till you step on your bicycle again (or your pump kicks in, either by a timer, or by a level switch)

It even wouldn't probably matter very much if the draining would happen a little faster than the proposed time: neither fish nor plants would suffer from a limited time when the system is not exactly coordinated if these moments would be limited to once a day. I even think that would be really flexible.

you could easily first finish writing a post (or a poem for that matter) instead of having to run to your bicycle at the exact hour.

BTW you can have floating rafts in your sump too if you exploit all passive oxygenation possibilities
and if these were limited to drop to a certain height by stoppers, you would get root aeration each time you empty your sump to below that level

electrical pump capacity can still be limited to just over top tank drain flow rate.

... we are getting nearer and nearer to the "crème de la crème" solution for your setup

and a lot of these ideas can be applied elsewhere too.

I would copy these last posts to your thread for further reference

and subscribe to the "best thread" contest if I were you.
je zou dat winnen met de vingers in de neus (flemish expression)

hear the champagne bottles pop


Frank

I understood FS to mean to exercise .... or pump...only ONCE in 24 hours Frank .... the sump would overflow if not the same size as the Top Tank. When the Top Tank is empty it is time to pedal .... or whatever! ... all that water back to the top!

If the water must drain in 12 hours with no AP cycling at night then have a valve to adjust amount to trickle into first bed... faster or slower.

If a GB was the size that held 5,000 litres of WATER when full....and we wanted 12 cycles through the day that would be 60,000 litres needed in the top tank to be trickle fed over the day. (Cycles would have to be 2 hourly if to go over 24 hours...... would 1 cycle every 2 hours be a problem? )

60,000 litres would require a Top Tank of 10m x 3m x 2m.... and the catchment below (the Sump) needs be the same.

10 x 4 x 3 would give 120,000 litres.... and 1 cycle every hour over 24 hours.... Whew! big. And expensive to build.

WOULD ONE CYCLE EVERY 2 HOURS BE TOO LONG IN SUMMER .... summer is hot here.... like in OZ.... I know you know OBO Probably going to say depends on stocking rate of fish too....ammonia levels

I love your idea more and more the longer I think about it FS!

you have not understood that your top tank consists of two "layers" of volume, Chelle:
one bottom layer that is CHIFT, below which level the water NEVER comes, so you are sure that your fish will always have ample water to swim in,

....and on on top of that room for a second (variable) layer where there is the amount of water you wish to pump around in batches.

There is no limit as to the volume of the CHIFT layer: it can be as big as you want. You can freely decide.
Same goes for each next fish tank: the CHIFT volume of the tank you can choose at will.
You need spare room in each fish tankabove the CHIFT volume equal or more than the contents of one set of growbeds to cope with the tsunami:

it must be able to catch all water from one set of growbeds quickly and then release it back slowly

This is why I would rather put a separate flout on each growbed instead of one on each set of growbeds: you will have more constant rippling in the water instead of a big surge every now and then, so passively generated DO will be more constant instead of with peaks.

the minimal volume required in your sump is the water contents of one set of growbeds (and that only to to avoid accidents if one day you wish to go rope skipping instead of cycling as then it will certainly overflow.
a better and more advised volume of your sump is the amount of water you wish to pump in a batch.

This can never overflow as there is only so much water pumped up in each batch

even if the flouts of two or more levels of growbeds would decide to kick in at the exact same time this would not happen as then room is created in the following fish tank or in the next set of growbeds.

The number of batches NEEDED per day depends
a. on your fish density for water quality and aeration and
b. on your daily feed rate for adequate nitrification.

The number of batches WANTED per day is for you to decide: do you wish to pump one a day, twice a day, four times a day...

as said above, the volume NEEDED for your sump is only dependent on the volume per batch as no more water can come down than you have pumped up

There is no need for 12 cycles in a day for the plants: nature does it in two (the tides) or in even less (floods)
in fact I believe that too much cycles will make your plants lazy and not encourage them to root deeply, which will make them much more vulnerable should there be an interval
that is a well known phenomenon in classic gardening: spray your plants when needed but don't spoil them.

So it is not when the variable layer of your top tank is exhausted that you have to jump on your bicycle: you do that best when the batch has cascaded down all the way and your sump is back full, and even then you can most surely wait a couple hours even on a very hot day: there is water in most growbeds (the level may vary from one to another), and the media themselves are wet (gravel, pebbles, sand) or even retain water for a long, long time (perlite, vermiculite, clay pellets, coco and other fibers ...)

but keep in mind that your fish need aeration, so don't exaggerate by taking two days off. As said, it is mainly fish density and daily feed rates that decide about the volume of water to be pumped.

... and calculate whether it is at all possible for you to cope with this:

http://en.wikipedia.org/wiki/Human-powered_transport

supposing you weigh 60 kgs that would make you capable of 180 watts in one hour
180 watts will pump maximally 9000 liters to a height of 6 m if your bicycle and pump reach 80% efficiency in that hour

I think you must consider this as an absolute limit if you must do it twice a day

gives you some new figures to start from:
18000 liters/day recirculation rate to calculate fish density and food rates
9000 liters sump tank (or less i.e. 4500 liters if you would exercise 4 times 1/2 hour each day)

and will no doubt keep your figure in perfect shape

ah, the wonders of Excel spreadsheets

we are hijacking this thread, Chelle, luckily mostly on topic

Frank

Hi all!!!!!!
This whole idea of the header tank as "battery" backup is one I have been kinda keen on all along. (It is something I sort of pushed a bit in Cyara's thread a bit.) I wish I had a site that would make such a thing reasonable.

Here are a few notes about such a system. Sorry, no I do not think a bathtub would be a big enough header tank to take care of a couple meters of grow bed. A bath tub would probably only serve a very small bin of a grow bed over a 24 hour period. Here are a few tips to help you figure out if such a system is really reasonable. It is generally accepted that a grow bed when filled with gravel will hold about 40% of it's volume in water. I usually just figure 50% so that I have some extra water and capacity in the system. If you want to be able to stock a fairly large number of fish, you will need to be moving the amount of water in your fish tank each hour. If your fish tank is say 10 l (tiny aquarium) and you were only going to fill the top tank once per day then you should have 24 times the size of the fish tank in that header tank and you also need at least that amount of space in the sump tank as well. So for a 10 l fish bowl system you would probably be best off having a header tank of 250 l and a sump tank of 250 l. The amount of grow beds for such a system can vary more but 20 l would probably be appropriate to an amount of fish comfortably living in such a small fish tank. Might be a nice energy efficient way to grow some salad while keeping some gold fish quite happy.

If you wish to size this up to a backyard system with a couple square meters of 30 cm deep grow beds, your header and sump tanks are going to get rather large. If you can manage a bit of a water tower platform (it doesn't need to be terribly high, just big/strong and able to support the amount of water) with it's bottom just above the top of the rest of the system. If you say wanted to use an IBC as a fish tank and were planning on stocking as many fish as you could and still only moving water from sump tank up to header tank once per day, you would need header and sump tanks of at least 24,000 liters each!

If you are not going to have very much fish, you can probably get away with less flow and therefore smaller header and sump tanks. The plants are generally happy with less flow, it is the water quality for the fish that usually requires more pumping.

Now the idea of the huge header tank that is filled up by wind/solar power or even off peak electrical power and then allowed to run the system without power for a period of time before running out is a wonderful idea and is a primary reason I think a header tank would be a worth while investment. It could even function as a "battery" back up for a regular continuous pump electrical system. If your site and/or materials/skills at had lend themselves to a large header and sump tank, then it would definitely be worth consideration. The size of the header tank/sump tank will dictate the amount of time the "battery" will last.

I personally recommend that a sump tank in a constant height in fish tank system should be able to hold enough water to flood all grow beds in a system plus some extra. Even in a cascade system. Yes, in a perfect world where nothing goes wrong and roots don't effect water flow, you should be able to have a system where the sump tank needs only hold enough water to flood one level of the cascade but I have seen times when flow rate slows down a little and for some reason the top level floods, trickles over and never quite drains until some one notices the leaf stuck in the flout or the slowed flow into an auto siphon bed. In which case, you could wind up with more than one level of the cascade flooded and if the sump tank doesn't have enough water to flood more than the first level, the pump has run dry and everything is stuck in this condition till a person comes along and re-sets things.

Hi TCL!

Is that 20 litres in your example in the GBs including or excluding grow media... ie 20 litres of water flowing through... or a 20 litre volume of GB built.


So in fact, if I understand you correctly TCL, true CHIFT is not guaranteed if done in series......
If level 3 clogs up for some reason and levels 1 and 2 above keep moving there could be a flooding.

Makes me even more certain I don't want things running at night....

Simple maintenance checks are essential. But hard to know an SLO is clogged by just looking at it unless is transparent. What is the biggest pipe size that could be used that will still lift solids?

And a flout? Only see it when flooding started that it is blocked?

I want more than one SLO per FT so that would ease things. Wanted 3 to be sure all solids lifted along the edge of the deep-end.

If I use a single quadruple flout then blocking of all four outlets is unlikely don't you think?

A simple overflow pipe in each FT and GB above max water height... again a good use for extra displacement capacity... should be able to draw off excess water and prevent flooding over the top. Just must be big enough... or enough of them... to move the water fast enough to prevent the flooding over the top.

For me to run the top tank as a battery.... and have to enlarge the sump to carry ALL the water travelling through makes the Sump impossibly big to build for me.... And I really like this idea of a stored battery of water above very much.

Aaaah!
Plants don't need the one hourly cycles..... fish do....... if stocked to capacity...
Can either have fewer fish or larger FT water volume....
I do like the latter option! Was concerned that my Fish Pond was inordinately large.... but didn't want to make it smaller becasue of the thermal protection it offered the fish.... but it also offers a buffer against ammonia spiking!

You can see me plodding through ideas that must seem plain as day to those who have been doing it some months!
Roll on my practical days too!

I still want the large Header Tank and large Sump..... for the "battery" storage of water

Big really seems to be better in AP. Oh well.... just takes more time to build as money comes in.

FS I hope you don't mind..... I am going to copy some of these postings to my member thread so I don't forget the info.... will refer back to here. Stuff gets so lost over time...trying to remember where something was read.

Here are some PVC adapters I have found. How would you use them?