I noticed some chemical burning on the tomato plant leaves and tested the water. 8.0 ph when I need 7.3. Ouch. Burn baby burn. While all three tomato plants have blossoms, only one is producing fruit and shows no sign of the chem burn.
I didn’t just test the PH, I tested nitrate, nitrite and ammonia. All were perfect for the system. For those readings, I couldn’t be happier.
Our well water is 6.0. For the house I “condition” it by running it through oyster shell to bring the PH up to 7.3 naturally. For a quick and very un-permanent fix to the problem I did a 2/3 water change in the fish tank and got what I expected, close to perfect PH. This, however, is a really poor solution. I flushed my nutrients (okay, I lied. I dumped the water in outside planters) and added kelp to compensate for the loss.
The whole point is to have a system I don’t have to think about or fuss
about or test or monitor or . . . you get my point. I cannot keep doing
water changes. I don’t want to have to add anything to the water to
keep the water at 7.3. Which means I’ve got to find a different media.
This media, as suspected, spikes the PH.
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.
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.
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.
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.
I’ve pulled my grow bed apart and gotten it stored away in the loft. I’ve put the hydroton in barrels and buckets for the winter. I’ve still got to pull the grow bed frame and cover the tank. Next year I’ll try and find a nice clean 55 gallon drum (plastic) for storing the hydroton. That’ll let me put it all in a single container. The 30 gallon drum I’ve got just isn’t big enough on its own.
Yesterday I rebuilt my aquaponic system to accommodate an additional grow bed. The single tray I used last year was just not enough. I have switched out the gravel I used last year for hydroton (expanded clay balls) so (theoretically) the beds will be light enough to move inside when the weather grows too cold to sustain growing. A single bed filled with gravel would require four muscle men, a pygmy goat and some special equipment. That so won’t work for portable beds. With hydroton I should be able to lift the bed onto a rolling cart for transport indoors.
Now that I’ve got two beds to flood, last year’s system won’t work as is. Two beds means at least twice the water volume. I will gang together two 5-gallon buckets to make up the required flush volume. By ganging buckets together using a short length of 1½ pipe and tee-less connectors, I can supply the volume for both beds using my existing fill and drain system bucket.
So far I’ve got one tray filled and water cycling through but I have more to do before I’m ready to consider planting. I need to cut new piping for the drain system. I want the system to flash-fill the beds so I don’t have to rely on an auto-siphon for drainage. That reduces the complexity of the system and reduces the parts needed to get additional beds attached to the system.
The tank’s water temperature is still below 55° [brrr] but if I’m going to get a head start on the season, I need to get my beds functioning mechanically now. To get the beds up to temperature a little more quickly, I’m thinking of installing a solar water heating system for the tank. We’ll see if I manage to get it done before the tank gets up to temp.
I’ve gotten four meals of lettuce out of my growbed so far. I don’t have a lot of lettuce in the bed . . . I should have a lot more. I’m supplementing with store bought lettuce.
I found a place to get hydroton in Olympia. It was max expensive, $40 a bag when the going rate is closer to $28. I bought two bags. That should be enough to fill both growbeds with a bit left over.
I pulled the gravel out of the wall gutter and replaced it with hydroton. I also trimmed the heck out of a bunch of plants in the grow wall to allow some slower growing things a little bit of daylight. I put some of the trimmings in the gutter along with a couple of sprouting grapefruit seeds.
The orchid in the wall is not doing well. I don’t know if it will recover or not. Time will tell. I should have moved it ages ago.
I long ago faced my addiction to plants and decided it was not a bad thing.