Backyard Aquaponics
A place to discuss aquaponics

There are many ways of keeping the base of the tank clean of spent food detritus and fish manure, and the method you use will depend on your system size, stocking density, etc....

My small ornamental system has never had the bottom cleaned, and there has never really been that much of a build up on the bottom, in the 3 years or so that I have had it running. There has been a few times that I've scooped out a bit of sedement, mainly fallen leaves on the bottom of the tank that might build up in a corner where theres a rock on the bottom of the tank, or a bit of pipe, where sedement naturally collects. But the base stays reasonably clean and this is because the stocking densities in this system are never very high.

In my larger system the Barramaundi would create a bit of muck on the base of the tank, this would always collect into the centre of the tank due to the fish generally swimming aroud the outside of the tank. Every couple of days I would use a fine mesh scoop net (from an aquarium shop) to scoop out the muck that had collected to the centre of the tank. This same system when it has more fish in it, has no problems with anything settling on the bottom of the tank. Fish are constantly stiring up the bottom of the tank and any sedement stays in suspension in the water, being sucked up through the pump into the growbeds.

There are a few other methods of collecting the muck off the bottom, pond shops sell vacuum cleaner type bits that run on water flow and are attached to your garden hose to suck up the muck from the base of the pond/tank.

Air lift pumps can be a great way to lift muck out of your tank, and a quick search online will find further instructions on how to make one simply by using an air pump and some poly pipe..

If the sediment is only fine, and not large leaves etc, then a large diameter hose can work well when used as a syphon to remove the muck. I used to have the end of a hose wired to the end of a stick so that I could start the syphon running then direct the hose around the bottom of the tank sucking up all the muck while syphoning it out into the garden.

There are many many ways of cleaning muck out of a tank.....

Hi All,
I found this site through Earth Garden, we already have a large, old rain water tank which is buried in the ground except for the last two feet, which is out of the ground and has been rocked up so it looks nice, it has gold fish in it and water lilies at the moment, it has been in use for around ten years and we have never cleaned the bottom or changed the water, mind you, it is not over stocked and the fish are not all that large.

I am wondering if it was to be incorporated as the fish tank part in setting up some grow beds and perhaps stocked with somewhat larger, edible fish if we would need to clean it out? It is about six foot deep and the same across.

Interesting site and topic Joel.

Abcalert,

Will be interesting to know Joels take on that question, but from my point of view i'd leave the tank as is.

The beneficial bacteria that we talk about will colonise any surface (its just that porus or rough surfaces give it more area) so if you have had fish established in this tank for a while then its almost certain that any surface area houses the said bacteria, which will reduce your cycling time dramatically.

Emptying and cleaning the tank will most probaly kill any coloines that have established.

If it was me i'd go ahead and set up the plant part of the system, then if u want to suck some muck off the bottom with the methods perviously listed do it in a few "go's" after a month or so.

Having it buried is probably going to help with keeping it insulated from temperature swings as well. Keep us posted!

Steve

G'day Abcalert,

Yep, I'd stick with Steves' suggestion, if the tank aint broke or leaking you can leave it as is, it's well established and will only aid you in setting up a system and establishing your bacteria...

You should simply be able to look at adding a pump and some growbeds while increasing your stocking of fish.. If you find that there's a bit of muck that is clogging your pump from the detritus on the bottom then you may need to clean a little out from the bottom. But for now if you want to set it up with some grow beds and more fish, I would leave it as is and see how the pump goes....

Is there a pump in it already, or is it just a pond?

Joel

Hi Steve and Joel,
Thank you for your suggestions, there is a pump in it which runs water through some ornamental otters, like a little waterfall, may either remove it from the otter waterfall or grab another pump, I think I can keep any pump far enough off the bottom of the tank so that gunge does not clog it, also I go have problems with the current pump as because of the way it is set up to run into the otters it is close to the top of the water and that green gunge you get in sunlit water gets into it even though I put a cover over it,

Will put the next pump lower in the water maybe? Do you have this problem with your pumps?
Cheers Abcalert

Here is my bucket airlift filter. You can grab the handle and lift it out of the tank and wash it every now and then to remove the dirt (but I am told to leave a little in there to recolonize good bacteria! - maybe a sponge, washed coral and some cuttlefish bone in the middle would be a good idea.) This one contains - washed shell grit, washed pea gravel and coarse washed sand .

When it starts to get really cold, I wil reduce the airflow a little and wrap some bubble wrap around the tank.

www.communisat.com/johnnie/FHT.doc

Regards

Johnnie

Hi Johnnie,

I like your filter....

My tank spent the winter wrapped in bubble wrap as well, it's a fantastic insulator when there are couple of layers of air bubbles.. I floated foam on the surface of the water as well, but the fish tended to rub against it and get sores on their back because of the foam.

Joel

Filter is performing way above my expectations ..

I am having so much fun with this concept ..

Maybe , when you get an afternoon off work , you can visit our school farm, whatever .

My year 8 kids are funding a barbie - late term 2 or sometime in term 3 .. we are going to eat the fish we grew! U will be invited!

Leeme know your address for an invite!

I have 2 big fish ponds I would like to get ready ...... would be great for goldfish .. but I think we should grow a non- competitive but unusual species ... something that no-one else is growing here in WA ...

any ideas?

many thanks ...

Johnnie

Here is an idea I have been thinking about for a long time ...

at this stage .. it is still an idea ! I have to get some nice long shallow trays for herb beds.

I like the idea becuase if I can get it "just right" . it will mean no electrical cables dragging all over the place.

I set up two wheelie bin tanks a few meters apart from each other using the air driven bucket filters decribed before in this thread.

Then I got hold of some weldmesh to make a sort of workbench that sits on the lip of each of the wheelie bins to form a sort of "tessle table".

The I use the airlift principle (tube within a tube) to transfer water to one end of the shallow (8cm) growbed tray sitting on the metal mesh grid. (Believe me .. I had over one meter lift with this airlift system! .. slow ... but I did get well over a metre!) , but 18 cm would be more than adequate for this idea!

The large shallow trays are fitted with a hole in the bottom or side so they don't overflow. Black retic pip is inserted into the hole and directed back to the tank from whence it came. (This can be adjusted to set the flood level!)

Voila!

The little pic added bleow shows how I did something similar with a small hydroponic system I made for 90 bucks a few years ago. (I used a manure / wood ash mix for the nutrient solution, and had to put stakes into the ground to cope with the weight of tomatoes I got that year!) AMAZING!

Anyway .. .. the black pipe is the return from the gutter channels .. the transparent hoizontal pipe is the airated water going into the channels, the "difficult to see" vertical pipe is the air supply - from an aquarium pump.

www.communisat.com/johnnie/hydroponicidea.JPG

Imagine doing something like this on a much grander scale with wheelie bins, instead of the white buckets, BIG shallow trays instead of gutter downpipe!

No electrical recirc pumps ... everything is air-driven - this means you have very few problems regarding location! You can run an airline virtually anywhere!

I have my two wheelie bins set up for this .. I got the wledmesh as well and am in the process of finding some large shallow trays for growing something like sweet basil , in small pots on the trays.

(The wheelies have fish in them already, some tiny koi and some goldfish!)

I think you should keep the idea of using the guttering Johnnie, these guys in Singapore have a pretty nice set up using guttering..

http://www.watercircle.com.sg/Aqua.html

I wondered about using air lifts for the system I'm building at the moment, but I think theres no way I'd be able to get the water up about 1.8m....

Have you tried to do a hydro system with just diluted worm juice, I have seen reports claiming the growth excedes aquaponics and hydroponics using conventional formulas, but then their experiment was flawed. They set up all three systems and started the trials immediately, not allowing anytime for bacteria to establish in the aquaponic system, as such the aquaponic system performed very poorly...