Backyard Aquaponics
A place to discuss aquaponics

With a lot of research and advice from this forum (thanks Guys) I managed to design and build my first aquaponics system.
I've ummed & arred many times but figured I'll be doing this for another 20 years or more and hate fixing things that could have been done the best I could've the first time.
Although not totally finished my system is cycling fishless as of yesterday! "Whoohoo". I still need to get another more efficient dry pump that will pump the sump tank quantity in 15 minutes, fit the auto-vent doors, get the 2 IBC's FT's I've been waiting for then plumb them in.
At the moment I set the timer for 0.5 hr on 1 hr off during the day and 2 hrs off at night. Of the 20 seedlings I put in yesterday 18 are doing great they don't seem to have suffered shock unlike a broccoli and a silver beet that were over crowding the wicking bed, they seem to be recovering slowly. More seedlings are on their way and I'm experimenting with using scoria fines in the black seedling tray to reduce handling of transferred seedlings.

Stats;
GB area: 5.52 m2
GB depth: 0.3 m
GB media: Scoria washed 1.65 m3
ST vol: 303 lt each.
Cycle vol: 480 lt
GB & ST material: 304# Stainless steel
Frame work material Galvanised steel tube

Pete.

Hiya Pete, looks great, well done. I noticed on Porters thread he pointed out a few problems with using ss regarding temperature issues, you may like to add some cladding and or insulation, temperature swings are not good for fish.
How is the ft accessed? What size poly pipe is that and are you planning f&d or cf?
Overall it looks nice and neat and once there are plants overflowing it'll look even better.

Hi Skeggley,

yes, some white colourbond panels with 25 mm polystyrene will be going over the surfaces not facing the shed.
Those two tanks below are sump tanks which I'm cycling from temporarily until I get the IBC FT's. The sump tanks are on rollers and can be pulled out to 275 mm allowing access to all corners.

The poly is 20 x 2 mm which I had to heat up to get over the fittings. Initially I was going to use 40 -50 mm Pvc pipe all the way from the slo but I'm struggling to find the appropriate fittings so that I can control the water flow
into each bed like the temporary way I've got it now. I'll plumb that when I get the tanks. These taps had several bars going across the openings to act as a filter so I drilled them out and now have 20 mm full bore.

What do you think is the minimum size pipe for the distribution into the GB's?

I'm using the F&D on a timer method, I've drilled an 8 mm hole 50 mm up from the base in the stand pipe that allows the water to drain out in about an hour.

Pete.

After four days of cycling fishless in washed scoria and town water I tested the water quality as follows:

High range PH 8.3
Ammonia 0.25 ppm
Nitrite 0.0 ppm
Nitrate 2.0 ppm
See pic.

The plants seem to be kicking along well.

What does this mean?


It's been mentioned to use Seasol to provide some nutes prior to the fish arriving but not knowing how much I put 1 cap (10ml) of Power Feed into each sump tank (303Lt) and see how it reads tomorrow.
What sort of levels should I be striving for?

Pete.

Hey Pete, levels? 1-2 ppm ammonia. I used, and still use Charlie Carp fish emulsion to cycle and as a supplement. Season and the like will not give you the ammonia you need to feed the bacteria.
Personally I prefer the PVC pipe over the poly, I stepped down from 40 to 25 usimg a mix of waste and pressure fittings.
If your pump is filling the beds from empty in the fill cycle then the sizing should be fine.
Your pH is a bit high but will help with your cycling. What is your tap water pH?
Hope this helps.

Thanks Skeggley,

town water PH is 7.6, I'll give the Charlie Carp fish emulsion a go. Yesterday I checked the levels (see Pic) and put 40 ml of Seasol into the sump tank. The ph seems to have come down a little.

I am thinking of leaving the 20 mm poly as is bar leveling out the top pipe and eventually entering through the left side from the larger PVC pipe. The distribution pipes below the taps have have 6 mm holes every 100 mm beneath and an open ends. Do you expect the 20 mm poly to clog up once the fish grow up ?

I got my 2 IBC's yesterday and plan on using 50 mm SLO's independently with a directional valve to send either of their waters to another series of GB's.

Do you or anyone see issues with any of the above?

Thanks, Pete.

If you need ammonia you use Seasol Power Feed instead of Seasol - it provides urea (goes to ammonia) plus all the other good things that Seasol normally provides to keep the plants ticking.

When you have nitrates in system and don't want any more nitrogen then you go back to normal Seasol.
It provides trace elements and potassium (K) with very small amounts of nitrogen and phosphorous.

IMO best way to apply is to mix it up in a watering can (cap or so) and then water it onto the grow beds.
That is where your bacteria is living anyway.... and plants get most benefit.
Particularly better to add to GB once you have fish.

I suspect the nitrates you are seeing are due to the liquid fertiliser and not because your system has cycled.
The true cycling test (for a fishless system) is to add pure ammonia to something like 0.5-1ppm and then see that it passes through to *nitrate* without any spike or build up in *nitrites* and all ammonia is gone within couple days.

when cycling without fish you can afford to have your ammonia up a bit (1-2ppm).
Go for green on the chart initially *BUT* only yellow once fish are added.

So Pete - adding Power Feed is correct. You probably just need a bit more or some ammonia/urea to kick things off.

seeing nitrates in the 0-20 range is fine, a working system can have quite high nitrates.
(mostly 0-80ppm so can get readings into red). Some run even higher.

FYI on the Charlie Carp vs Power feed

From a gardening web site.
The Charlie Carp 'new formula includes trace elements' variety - uses whole fish, rather than fish scraps.
Analysis W/V is Nitrogen 9.0 phosphorus 2.0 and Potassium 6.0.

Powerfeed is 'an organically based fertiliser, and contains highly active liquid compost which acts as a clay breaker and reduces nutrient loss in sandy soils. It stimulates growth of beneficial microbes which break down organic matter and release soil nutrients. Nitrogen 12.0, phosphorus 1.4 potassium 7.0 potassium humate 3.08.

It would probably be hard to identify the difference in the garden. Of greater interest is the different dilutions recommended. Charlie is 1 to 100, ie 100ml to 10 litres of water, then a monthly dose, eg flowers, shrubs 20 ml. Powerfeed is 45ml per 9 litres of water for similar plants.


The main difference is that Charlie Carp has protein, amino acids and organic by-products in it from the fish. Nitrogen in Power feed comes via Urea. CC also has slightly higher phosphorous and slightly lower Potassium. The full Power feed and Seasol trace element list is on the Seasol website here http://www.seasol.com.au/documents/Prod ... ntrate.pdf
couldn't locate the Charlie Carp one.

The main risk with CC (that pops up around the forum) is that you can get a fairly decent algal bloom from it.
You woud also get it from too much of PF or other liquid ferts - particularly where phosphorous is being added.
To get elevated ammonia probably best to go with pure ammonia or urea.

Not intending to dispute Greg (Skeggly) as he has a bloody good setup and I have no doubt that he and others use CC just fine. However I feel it is important to clarify the Seasol comment to avoid confusion or the wrong messages being taken.

The simple message is that whatever you add to your system you must be 100% aware of what it is adding and why.

p.s. for the ammonia test (pure ammonia or urea) you add to fish tank (WITH NO FISH) to test that the ammonia the fish are going to produce disappears - which if you think about it is exactly what you want to happen when fish go in.

Once fish are in IMO it is better not to add things to the fish tank - that way anything that does get through is somewhat diluted. Any supplements for plant benefit should go to the grow bed - the plants need them not the fish.

p.p.s Yep Pete - IMO 20mm poly clogs up much more easily than PVC. I have less issues with 15mm PVC than I do with 19mm poly. The other issue is many poly fittings go inside the pipe and cause constrictions and clogging points. PVC fittings sit on outside. You also tend to get cleaner weep holes in pvc.

Thanks Darren,

I'll chew all that over.

Pete.

I agree powerfeed would work as an ammonia source.
Getting an algal bloom or pea soup is pretty much an AP initiation regardless of ammonia input and once clear again it's rare to reoccur.
I'm assuming you are going to clad your ibcs to keep the sun out?
Using slo's from ft to gb pulls out the fish waste whole which can block smaller pipe work, putting a filter in line can solve this issue however it does add more work fitting the filter and routinely cleaning it. I have a 40mm slo in a 1Kl tank with multiple 10mm holes around the base which works ok but I do need to meter my inflow as too much will fill the tank to the top of the slo but I like to keep the holes small to keep the sp tiddlers where they should be, I think 50mm will be fine. I don't glue anything in the ft and can disconnect the slo assembly for cleaning purposes. Make sure the top of your tee on the slo is below the top of your tank for overflow purposes.
The most important things are, not to overcomplicate, remember you will go on holidays, and have fun.

Thanks Guys,

if the slo has a T on top and the water gets up there wont it be full already? It either can't get rid of the water quick enough due to blockage or the pump is supplying too much. After that it will flood out through the lid, to prevent that should a over flow to another container be fitted?

I've seen posts that endorse the use of larger dia. slos but they don't mention their flow rates. I figure the larger the pipe the slower the flow. 50 seems to be the norm but I'm going to run the next 12 m to the GB's in 40 to increase the flow so crap doesn't get settled as easily and because I've got to go down under ground then back up again over the GB and difference in height of about 700 mm (head). the pump flow rate will be about 2000 lt per hour 15/45. See any issues with that?
I saw a video on the net of a slo pickup flange that sits on three ss bolt heads just 4-5 mm off the bottom of the tank which allows 360 deg access for crap sliding towards it to be sucked in. I found the fitting at Bunnings for 50 but not 40 dia. Although a heated end of a 40 mm pipe pushed over a funnel for flaring then the edges flattened of on a table might even be better to maximise flow at the point where it wants to restrict.

Pete.

The idea of the open T on top of the SLO is that 1) it won't start siphoning and drain your tank, and 2) if the bottom intake gets blocked (dead fish, poo clogging small holes) it keeps draining. If there's any risk whatsoever of the whole pipe getting blocked then yes, a separate overflow outlet is a very good idea!

Personally I'd leave your piping all at 50mm, and also put in an inspection pit at one end of the underground section with a screw-on cap I could use to flush gunk out of the pipe. I'd be worried about the corners reducing the total possible flow rate and the lowered section collecting settled gunk - I'd want the wider piping to compensate for the friction caused by the long distance and multiple bends.

Excellent job!

I'll agree with the others about the poly pipe from the pump, you'll be loosing efficiency from the pump due to friction from the narrow pipes.

What size pump do you have? You can calculate the pipe size from there.

I've been meaning to get into stainless steel welding, what gas do you use on yours?

Easiest way to weld stainless is with sticks

Dare I say it, it's possibly even easier to weld than normal mild steel

I tried welding with sticks a while ago, but it was on thin material and I kept on blowing holes.