The trial

6" pvc with survey end caps.
6″ pvc with survey end caps.

For a couple years my brother Dan was a maintenance engineer at a produce processing plant. He did a system retrofit and brought me some of the stuff being thrown away. This flood and drain planter is a piece of 6″ schedule 40 pvc pipe. The ends are survey caps purchased at a local plumbing supply warehouse.

The really sick looking plants are the result of neglect on my part . . . pulling one system apart and putting another together with too long a span between stressed the plants. They’re recovering. The tomato plants are purchased and are my test subjects. The tank holds two goldfish, not quite enough to supply this many plants with nutrient.

One of my concerns with media this light is its ability to hold the plants in place as they grow and produce fruit. I will have to run retaining lines between the support ropes.

A question of media

Ugh, it floats
The failed floaty stuff, the new light clay-like stuff and hydroton.

In planning my next plant wall I’ve been testing hydroponic planting medium.  In the past I’ve used hydroton but there are currently two issues with this media.  Because it’s heavy in iron it eventually trashes the magnetic pump.  I replace pumps about once a year.  At about $50 a pop that’s not horribly expensive but it is inconvenient.  Secondly, it’s no longer available.  That makes the inherent equipment-related problems with the media moot.

Leftmost is the floaty stuff, middle is the light slippery-clay feeling media.  Rightmost is hydroton.
Leftmost is the floaty stuff, middle is the light slippery-clay feeling media. Rightmost is hydroton.

I bought two bags of a product that was supposed to be a replacement for hydroton.  It felt like sandpaper, very garnet/scratchy expanded glass feeling.  The pieces were quite large for hydroponic media, didn’t break when whacked with a hammer and very light.  Other than the roughness and overly large size, I thought it would work fine.  Wrong.  The stuff floats.  Using it in a flood and drain system allows all the plantings to shift every watering cycle.  When working with seeds, the media used to hold the seeds vanishes into the mix.  Ugh.  When planting cuttings they sink a bit into the mix every cycle eventually drowning.  Double ugh.

Light with a slippery-clay feel
Light with a slippery-clay feel

I reported the failure to the excellent staff at our local hydroponic shop and got a sample of another product to try. It had a light silky clay feel, sank when dropped into water and could be crushed.  The product is a little big, roughly 2-3 times the size of the hydroton beads.

PH is one of the most important items to monitor in a hydroponic system.  I’m not a fan of chemicals and like to handle this as naturally as possible which makes the ph of the media very important.  With that in mind I crushed a piece of the new media and tested the ph.  It tested lower than I expected at 6.0 which means it’s not inert.  Because our water has a very low ph which I moderate with oyster shell, I’m keeping an eye on my test system. Time will tell.

Moving on

I’m the type of person who continually tweaks and adjusts.  Some of the stuff I try is a bust and some is inspired.  I have a rack hanging over the back of my kitchen sink with a drip tray under it where dishes are set to dry.  It keeps my counter space clear and allows all the drips to fall into the sink.  Brilliant.  And I’ve done other things with far less stellar outcomes, they’ve inevitably led to ideas about other things so it’s all good.

Here's the plant wall winter 2013
Here’s the plant wall winter 2013

There are a lot things I like about my current plant wall, and few things I don’t care for. Because the plant wall surface isn’t covered with plastic ala P. Blanc, the rate of evaporation is significant.  Wadly adds roughly 6 gallons of water twice a week.  I’d like to reduce the evaporation.

Dying foliage allows pathways for water to drip onto the floor.  A change to prevent that in future is a must.

Slow growing smaller plants get crowded out by the bigger, faster growing plants.  They just can’t compete.  I’d like something that nutures both the big and bushy and the smaller, more delicate plants.

As this plant wall is a single piece, it’s heavy and difficult to move.  Repositioning plants and editing is difficult.  I’d like something a little more modular that takes up less vertical space for the same number of plants that allows the fish to be as much of a focal point.  At this point I can’t tell you what’s in the tank, other than healthy reproducing guppies and at least one fresh water shrimp.  I’m sure there are algae eaters and plecko in there as well but I haven’t seen them in . . . a really long time.

So, on to the new plan, something modular with less exposed surface area that will allow for planting a few seasonal edibles and allow us to see the fish.