Backyard Aquaponics
A place to discuss aquaponics

Hi All!

I have designed this system considering remarks and discussions found in this forum.
It is working now for one and half month at basement - started on March 15th.



My setup consists of two GB (2x60L) and a signle 60L FT (old aquarium).
Each growbed is made from food grade plastic box 60x40x33cm. The last number is depth.
They are filled with rinsed hydroton (here it is called Keramzyt).
F&D is realized with overflow standpipe having additionally a small hole (5mm) at the base.
The standpipe is only pushed in into the fitting (no glue). It can be removed
at any time for replacement/maintanance/shortening. This is possible because it is
surrounded by outer pipe (shield) with plenty of small holes (4mm).



GBs are placed on the old table. At the front they stick out slightly from the desk top
so the drained water can freely fall back to tank. I added only some curved flexible pipes
at the bottom to minimize flow noise.



There are two pumps in the FT working at diffrent times. Opposite end of garden hose
(also food grade) to the one attached to pump outlet is put on top of GB gravel.
Pumps are controlled with two simple segment-type 24h timer switches.
Each pump is ON for 15min (single segment).
Single pump cycle takes 2 hours. One pump is being turned ON every odd hour,
the other every even hour. In FT water level drops to about half every signle hour.
Filling GB takes 10-15minutes, draining about 20minutes.



To start nitrogen cycling at the beginning I was adding only small portions of
NH4NO3 with no fish in the tank. After 10 days I stared adding fish.
Now I have 3 platies and 17 white clouds ( is anybody using those fishies for aquaponics?).
After 5 days from startup until now the water is crystal clear.
Looks the filtration works perfect, hovewer nitrate level is too low (5-10ppm)
and pH level to high (7,5 in soft - mostly RO - water)
I am planning to double fish load soon. For time being I started to apply DIY NPK fertilizer
and a few drops of micro.

The main light source is a single 150W Metal-Hallide lamp working 14hours a day.
It is mounted to the ceiling centrally over GBs at distance 90cm.
Receintly I'd started also 150W HPS (on for few hours a day) hanging aside close to tomatos.
The plants are lettuce, chives and cherry tomato. Tomatos are big becuase they
already grew for some time in DIY hydroponic shallow F&D system which I had before.
Surpisingly, tomatos are growing the best (possible because of low nitrate level).

Be very careful adding any sort of fertilizer into an AP system!!!!!!!! If you are showing any nitrate, it is probably enough. Patients!!!!! It takes time for an AP system to mature. Most people only add stuff like chleated iron and some sort of sea weed extract (like maxicrop or seasol) to provide potassium and trace minerals. Some amount salt is often added too and it provides some trace elements as well. Be very very careful about anything else you add to the system as fish can be sensitive to many things as can the bio-filter bacteria.

Otherwise, looks like you are doing great!!! Tomatoes seem to love AP by the way and the fact that you think your nitrates are low is probably because your tomato plants are sucking up the nutrients greedily. If you have trouble getting them to fruit, you might add more potassium to the system and if you can't get the sea weed extract, I've used murate of potash (potassium chloride) in small amounts (very small amounts for a system your size) and been ok.

If your plants seem tall, pale and scrawny, then they may want more light!

Keep up the good work!!!!!!

I'd definitely recommend covering the sides of those grow beds to prevent an algae buildup.

My DIY fertilizer is as for aquarium-like and I am sure it is NOT harmull to fish.
The only my concern is possible accumulation of ballast in time.
But the only ballast are sulfates (in K2SO4). and if I notice pH going to much
down I will just replace K2SO4 by KHCO3 and then I have no ballast.

Anyway I am not going to rely on fertlizing it is just for a better balance and
addition to organic AP.

According to suggestion from tamo42 I have covered GB with black adhesive tape.
This was a good point - I noticed algae were just started to cover internal side of transparent box.

After treatment with growth regulator (hormone) the biggest tomato plant already
has small green fruits (about 10).
This is actually the only chemical agent I am using. It is applied directly and only to flowers.
It is called Betokson S - probably local brand. It causes start of fruiting without pollination.
Its usage was recommended by "an expert" from another forum (home gardening but not aquaponic).

(Info from leaflet: Not very harmful for people - cl.IV practically harmless for bees - cl.IV practically harmless for fish - cl.IV for different aqueous organisms: - of daphnias - practically harmless - cl.IV - of algae - practically harmless.)

Fish load was increased by adding two goldies - veiltail species.
They are Not fast so my prediction is that white cloud minnows will not be eaten.
It looks actually they like each other

Regarding fertilization - I am now adding only potassium (KH2PO4, K2SO4) and magnesium (MgSO4).

Just to update what is going on 3 months from startup:



Now I have 6 goldies and about 20 minnows in FT. Fishes are well.
Lettuce is growing much better. Only roman spice
(the most demanding one) is still weak.
Tomatos are fruiting regulary hovewer their leaves are Not looking well.
Curled and dried edges.
I guess this is due to not perfect pH - still 7,5. Don't want
to go down - probably my hydroton contains some lime.

Occasionally, I am adding - K, Mg and micro - in mineral form (micro chelated).

Pretty good set of tomatos there Roberto... they'll be sucking up all the nutrients available...

I'd give the system a touch of Chelated Iron.... and some Seasol or Maxicrop... reckon that'd perk things up a bit...

All in all, not bad for an indoor system mate...

The system works now 9 months non-stop



I did some enhancements:

Lightening

After I had noticed symptoms of light deficiency on plants,
I added Fluorescent lights special for plant grow
and I lowered MH lamp position (about 40-50cm from plants).
It looks for me that amount of light was OK (HPS is producing
quite a lot) but there were shortages of some critical spectrum sections.
Now it is: 96W FL (Fluora and Grow-Lux), 150W MH and 150W HPS.
FL - 16h a day
MH - 12h a day
HPS - OFF now

Flood and drain cycle

More frequent - 15/60min during day and 15/105 during night

Fish

4 goldies and around 20 minnows - there were some fish problems
only for the first 3 months, then until now - everything's fine.
Fish load is going to be rather low.

Fertilizing

System is run something between aquaponic, hydroponic, aquarium way.
I am adding fertilizers and I am doing small water
changes. I am taking this water for ornamental pot plants watering and
it is replaced by RO water. This gives 1/20 of water changed per week.

My intention is to keep low biological load because I have small aquarium
60l and I do not keep eatable fish, so there is no need to stuff them
with plenty of fish food. On the other hand I want to obtain high efficiency
of plant cultivation. Additionally I found self-made fertilizer made from
pure chemicals to be cheeper and safer (if done properly) then extra fish food.
Fish task in my system is to help maintain helthy microbiological
environment - providing food for bacteria than producing fertilizer.

Macro self-made fertilizer is made from purified chemicals: NH4NO3, KNO3, KH2PO4.
(note that above compounds have no chemical ballast.)
This macro is added 4-5 times a day with a small amount by means of
automatic doser. This is to avoid NH4 level spikes in water.
NO3 level is kept around 40ppm.
I am adding also ready-made (hydroponic purpose) micro fertilizer on daily basis,
sometimes with extra iron.
Occasionally I am adding also MgSO4 and K2SO4.
Recently, I have discovered that a tip of powdered brewing yeast added to water
stimulates well roots growth.

Plants

Mostly lettuce also kohlrabi, celery, chives and melissa (lemon balm).
Taste is delicious!




Water parameters

After putting net bags of peat to the tank pH has lowered from 7.6 to 7.2
(it took a month). Now it is stable at 7.2. As I mentioned in my previous
description, my hydroton contains some lime and tends to level up pH.
Small amount of dishwasher (no iodine) salt was added making solution
of about 60ppm.

Images disappeared in this thread as hosting service I had used failed.
I am puting new ones more up to date.



System is running step by step more efficient. I am gaining real experience
about fertilizing and water chemistry because my system is run
as aquaponic/hydroponic hybrid which seems to work well, hovewer, it is tricky.
It is assumed that organic load will keep healthy microbiology while mineral fertilization
ensure balanced plant nutritioning. Lowered organic load should also lower problems
with clogging of pumps and hydraulic. Actually I hade experience 4 times stopping
pump with pieces of gravel thrown by goldies.

Lighting is now 150W MH and 100W FL - it is slightly too low but I will keep it.

Fishes are 3 fat goldies, they are living here from very beginning of the system.


I am using automatic feeeder and fluid doser as you can see.

Plants:
Melissa (lemon balm) - the lowest one
Parsley (two kinds)
Basilica (red one)
Lettuce
some chives



pH was stable for months precisly at 6,8 without any chemical stabilization,
which surprised me. Possible clay pebbles contain some lime or this is the result
of biological stabilization.

Fertilising:
I am using own made macro fertilizer consisting on no or very few ammonium.
NPK formula is 4-2-7 which is hydroponic grow-like formula with decreased amount
of Nitrogen. This is balanced by fish waste high N contents. The macro fert. contains
NPK Ca Mg S. This fertilizer is applied several times a day automatically and sometimes
extra manually.
Separatelly commercial hydroponic micro fertilizer is applied. I have choosen one which
has also good opinion for aquaristic purpose because of its high Fe:Cu ratio.

Recently, RO water used for refilling is mineralized with Mineral Magic GHE.
I am pouring a spoon of this yellow powder to the bucket when RO water is kept
and then water over the sediment is used. Powder itself is discarded.