Aquaponics - PVC Tube tomato

My PVC tube tomato seems to have found it's feet.

It took a while after I removed all but four or so leaves on each of the four plants that make up this particular experiment.

 It's probably back to around what it looked like four weeks ago.

By my standards, that actually constitutes success.

On a side note, the foliage in the background is the grow bed that I emptied and flooded around five weeks ago (flooded to get any slugs out).

That's lettuce you can see, and we've been cutting a salad a day from just that right hand side. The left hand side was Bok Choy, but that all went to seed, and has since been fed to my worms.

When I put the seedlings in (bought from a shop) I also sprinkled some mixed lettuce seeds around.

It looks like this five weeks later.

We've been harvesting from the front, and you can see some of the seedlings from the seeds are looking a little weak because they have been struggling for light, but now they have some, they will spring to life.

In summer, and harvesting a light lunch size salad each day, (in Adelaide South Australia at least) we found you need around half a blue barrel worth of growbed real estate, as long as you seed every week.

I like coz lettuce because it can be harvested as it grows (ie just cutting off leaves rather than pulling up the plant) , but these loose leaf varieties are proving to be quick growing, and can also be repeat harvested. if you drop seeds in around the seedlings when the seedlings are around the size you buy them at, the seeds are seedlings when the lettuce has been repeat harvested as much as it can, and finally gets pulled out.  I just read that again, and I think all that means something. 

The leaves get bitter toward the end of the lettuce life cycle as they are about to go to seed. The leaves  also grow further apart. So once they start growing from a stalk rather than from a central point at the base, it's time to pull the plant up, and let the light in to the little ones, that are by this time the size of the store bought seedlings.

I don't think I've ever grown the iceberg style lettuce that grows like a cabbage, so I don't know if you can repeat harvest that, but I suspect not. 

I used to take a lot of care with growing lettuce seedlings, and transplanting them, but now all I do is put a stack of different seeds into a jar, and sprinkle a pinch of them around directly into the growbed. 

I suspect the clay balls are better than scoria when you direct seed. I think the seed (especially small seeds like lettuce) fall down until they stick to the side of the media once it's deep enough that the media is damp. 

I suspect that's just right as far ar growing goes. 

Perhaps with scoria, the seeds catch in the holes in the media before they get to the correct depth. 

Or it could just be luck, but I'm seeing much better germination rates in the clay ball media. 

But it's also a constant flood grow bed, so perhaps that's got something to do with it as well. 

120 Things in 20 years - Results, but no science to back it. Oh, and also PVC Aquaponics tomatoes.


  1. Dear prof. Bullwinklell,
    Just finished reading most of your blog and, in between laughs, smirks, and general merriment, I believe I've learned quite a lot that I'll steal, borrow and put to good use in my own (much smaller and indoor) Aquaponic system. Just thought I would thank you for the time you've spent redistributing your acquired knowledge!
    All the best,
    Kasper (

  2. Thanks Kasper, It's nice to think I've been of some use :)

    Those tomato plants have turned into a monster since this post.

    I just went to your site, and I recognise the pictures. I'm not sure where from, but the words "planted aquarium" spring to mind.

    A magnificent setup. I've always enjoyed those fish tanks designed in a way that you cant see all the fish all the time.

    One day I'll build a house with interior walls all made out of rainwater tanks, so that I can cut viewing windows in each room and the fish can look at the humans at will :)

    Fish tank walls would also be an excellent heat sink for the human living space. The internal temperature would be like being in a cave.


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