Goldfish Barrelponics Update 2

I wrote a previous post about my goldfish barrelponics.  It started getting too long so I am writing a second update with plants that work well in the longer term. 

After my barrelponics had been going well for almost two years I decided to clean out the gravel pot as it was full of roots.  I removed most of the plants, tore off most of their roots, and roughly cleaned most of the gravel and added it back to a milk bottle.  I had to cut the old milk bottle apart to get the gravel out as it was completely full of roots, so I have put everything back into a new milk bottle.  I then replanted a small amount of the plants.  

The few plants that were replanted were trimmed heavily to encourage new growth.  As you can see in the photo below, I did not have many plants after the cleanout.

Milk jug after being cleaned and plants trimmed 

I keep hearing how tomatoes are well suited to aquaponics.  So last summer I tried to grow some tomatoes in the goldfish barrelponics.  They grew, and produced some fruit, but they didn't love it.  

My soil grown plants out grew and out produced the aquaponic grow tomatoes.  I think this is because the tomatoes needed more room for their roots than the crowded 2 liter plastic milk bottle.  If they had a decent sized grow bed I think they probably would have thrived.

Starting to produce tomatoes

Tomatoes growing but not thriving

I tried growing watercress.  This did well, it grew and flowered and set seed, seedlings grew and flowered, but it was eventually killed by cabbage white butterflies.  Watercress grows best with cooler temperatures, so I will likely add some back in autumn once the butterflies have passed.

I tried growing variegated water celery and this did tremendously well.  It grew long runners into the water and over the side of the barrel.  I cut it back hard and pulled out arm fulls of the stuff.  I cut it back hard a few times.  Unfortunately I think I pulled out too much the last time as it hasn't really grown back after that.  It may do ok now there is room in the jug for its roots to spread so I have added a tiny plant to see how it does.

Mint and silverbeet failed to thrive in my gold fish barrelponics.  They both did ok for a time, but didn't thrive and they are no longer growing in there.  I find this odd as mint is known to be overly aggressive in aquaponics, and silverbeet growing in my garden gets truly massive.  Perhaps it is too sunny or not sunny enough or something where my barrel is.  I think mint could work well and I may try to grow mint in there again one day.  

I tried kangkong in the barrelponics, it failed miserably.  I honestly believe kangkong would love aquaponics, but it is not suited to my climate.  That's too bad, I really like kangkong.  I will have to grow kangkong some other way.  Perhaps kangkong would do better in aquaponics if protected in my greenhouse rather than exposed to the elements like it is in the barrelponic.  I should write a blog post on this later.  

In my climate, for longer term growth with less work from me, Vietnamese coriander seems to be the winner.  Vietnamese coriander grows very fast, and seems to survive a lot of conditions that are meant to kill it.  It seems to clean the water really well.

As well as growing Vietnamese coriander in my barrelponics, I also grow some in the garden and some in my greenhouse.  The greenhouse plants have their roots in soil that is an inch or so under the water.  It seems to do quite well growing as an emergent pond plant and gets pretty big.

Vietnamese coriander in greenhouse a few weeks after planting

Vietnamese coriander grows large.  Watercress spilling onto the floor 

I cut off the Vietnamese coriander from my grow bed from time to time.  This makes the plants grow faster and quickly suck nutrients out of the water.  

After cutting it off I feed some to the chickens or put it in the compost, and last time I put some in a container with some water with the plan of doing something with it later.  Then I forgot about it.  Sometimes I would see it go limp so I would top up the container and think I should do something with it later, and each time I would forget about it.

This edible herb loves water, it smells great, and grows fast.  Below are the roots that the trimmings grew using nothing but water.  As you can see, they pretty much filled the entire container with roots.  There was only water and a few cuttings, no soil, it turned into an almost solid block of roots.

This Vietnamese coriander with that block of roots gives me options.  I could throw it into the compost, I could remove most of the roots and plant it in the garden where it would thrive, or I could use it for something else.  

In my greenhouse I had a tub of water filled with algae.  This tub is adding weight so the wind didn't blow my greenhouse away.   

After two days the water was still green but noticeably less turbid, and the roots had grown noticeably.  It didn't take long before the Vietnamese mint had cleared the water!  Now I am considering putting some fish in that tub.  From memory the tub is only 42 liters so is a bit small for goldfish, perhaps a smaller cold water fish would do well in there.  

Having a small aquaponics set up in my greenhouse sounds like fun.  It could be similar to my barrelponics, but with a different species of fish and probably a flood and grow bed on the shelf above so I can grow some edible plants in there.  Being in the greenhouse, perhaps kangkong and other tropical vegetables may perform well in that grow bed.  

Vietnamese coriander about to go into its new home

I am really impressed with my goldfish barrelponics.  For almost two years it has worked well, and I have learned a lot from it.  The original ten fish are all still all alive, they have all grown, and they have laid eggs a few times.  I am enjoying my fish and putting in very little effort to keep them healthy.