Fish tank aquaponics

[sthh]

Project: Fish tank aquaponics.

Decided to tranform my 4ft goldfish tank to grow vegetables, powered by nutrients provided by the goldfishes. There are currently only 5 small goldfishes and some cories. I reckon the goldfishes will grow bigger and provide more waste in the future, so not adding anymore livestocks.
Current setup has already been running for few years, so it is actually a simple modification, using the backup overhead filter and pump to tranport aquarium water to the plants.

Some consideration includes:
Lighting
Growth bed
Pump and pipings
Height of plants
Nutrient to plants
Additional waste coming into fish tank.

Lighting:
I tied my 4 tubes T5 lights to the top of the aquarium stand, to provide growing light to the plants.
A timer will switch on the lights daily at 1pm, and switch them off at 8pm. I think I will start with 2 tubes first, and monitor the results.


Growth bed:
I will be using a stackable overhead filter as the growth bed.
Went over to my trusty aquarium supplier, Yishun618 That Aquarium shop, and got my supplies. As a member, I get some discounts.
Here's what I got.
A stackable OHF base ($20)

3 Stacks OHF tray ($4 each)

My existing net pots. Each tray can fit 8 net pots, so I can grow 24 pots of vegetables at any one time.


Pump and pipings:
I will be using my existing eheim 101 pump which can deliver 600 litre of water per hour.
Bought a Y tube ($2.5), and 6 rainbars ($3.5 each) and 6 connectors ($0.5 each).
The Y tube and 2 sets of rainbars will provide water to 2 rows of net pots.


I assembled the rainbars, and using some existing rubber tubes I have to connect the Y joints and rainbar, and to my existing L bar that connects to my eheim pump.

Next, I use my soldering iron to cut some curve on the tray, so that the rainbar can sit nicely. Using black tape to secure the rainbar in place.

Moment of truth: the pump is turned on. Everything works like it should. No leakage, which is an aquarist's nightmare. Noise level from dripping water from the rainbar is quite acceptable.




Height of plants:
I will be growing short plants, as height between the light and growth bed is only 15cm tall.
Nai bai and weeks old spinach will be prime candidates.

Nutrients to plants:
Mostly nitrogenous waste from fishes. I will not be supplementing iron or potassium or phosphorus, because I am growing leafy vegetables and harvesting them in weeks. But if they fail the taste test, then I might add more fish safe fertiliser.

Additional waste coming into fish tank.
I will adding additional white wool to act as mechanical filter. Not too concern about biofilter for the fishes, as there is one existing 4ft established OHF filter in place.

[sthh]

Sowed some nai bai seeds on wet aquarium wool. Hopefully they are still viable and will sprout.

[onlyyouknow]

Nice project. Had a similar idea but didn't carry out because need a lot of lights to grow the plants well. In the end, just use the power of the sunlight and did a hydroponics without fishes and just dose fertilisers every week. My mint is growing very well and I can harvest every week.

[sthh]

Originally Posted by onlyyouknow

Nice project. Had a similar idea but didn't carry out because need a lot of lights to grow the plants well. In the end, just use the power of the sunlight and did a hydroponics without fishes and just dose fertilisers every week. My mint is growing very well and I can harvest every week.

I was going to switch on the lights for the fish tank for 6 hours a day anyway, so I thought why waste all the light energy. Hence I added an OHF tray to grow vegetables.
Here's some nai bai I've grown previously on hydroponics on a single shoe box. With a 4ft OHF, I think the harvest will be tripled.
Good thing is that I can control the amount of light.

[Ralliart_Ray]

This is an inspiring thread, where can i get seeds etc? Thanks for sharing

[yanki2]

hows the taste of the vege?

[sthh]

Originally Posted by Ralliart_Ray

This is an inspiring thread, where can i get seeds etc? Thanks for sharing

I got my nai bai seeds from a street vendor in feng shan, but you should be able to buy seeds from other places including grocery mart.

Originally Posted by yanki2

hows the taste of the vege?

The nai bai taste extra crunchy and sweet when I harvested them.

[sthh]

Roots are developing on these 1.5 years old seeds. Time for a transplant.

[sthh]

Water parameters are still not right even after 1 week of no water change. Good for the fishes, bad for the plants.

[onlyyouknow]

What do you mean not right for plants? I thought low nitrate is good meaning the plants are taking up the ammonia before it gets converted to nitrate. I remember taking in ammonia requires less energy for plants, or is it nitrate. Haha cannot remember liao.