I set up my aquaponics raft bed last fall but haven’t done too much with it so far. I couldn’t find any 2″ foam so was stuck with 3/4″ and that isn’t really high enough for keeping the seedlings from water logging if I were to drill holes and place net pots in the foam.
Capillary Matting edge over foam
So instead, I placed capillary matting over the foam so the edges hang in the water and I can place seed trays or pots or even peat pellets right on top of the matting and they stay moist. Granted, doing the wicking action like this isn’t really like growing things in the recirculating part of the aquaponics but the raft bed is only an add on for my system as I have plenty of filtration already. I have tested out a few things in the trays and pots but coir seems to work as does a coir potting mix but beware of possible leaching from the pots into the system during a heavy rain.
pots on capillary matting
Sunflower shoots in pot
Now I’ve found a 4″ pot of sunflower shoots or pea shoots to be plenty for a couple of people’s salads for a day or two. The large trays would be more appropriate to commercial aquaponics pea shoot or sunflower shoot production.
Pea shoots
To harvest the pea shoots or sunflower shoots simply cut above the soil line and wash them. They are great raw in salads but also as cooked greens or in stir fry. Ive heard that sunflower shoots are a good source of vitamin D and if you stir fry shoots, the stems provide a texture in the meal almost like rice noodles so could be a wonderful way to reduce carbs in a meal.
Sunflower shoots
The leftover coir or potting mix with the roots and seeds left in it make a great worm bed feed stock (I learned this from Growing Power who grows huge amounts of shoots in trays of worm castings mixed with coir and once the trays are harvested, the contents of the trays go into the worms bins for re-cycling.)
Wait… I think I need more information. What is the danger of the coir leeching into the system? I’ve got my seeds in coir-filled pots, and stuck those right into the growbed. If that’s going to be a disaster, I’d like to find out right away! TIA
No I don’t think there is really much danger in straight coir as long as it is just small amounts. The danger I was speaking of is if you were to use potting mix that has anything added to it like fertilizers.
That said, coir does break down in aquaponic water and could leach some tannins that will tint the water and could affect the pH if there were a large amount of it and I’ve even heard of some coir that is soaked in salt water which could be negative for some plants but in small amounts I don’t think any of these things are too big a concern.
Now with coir filled pots, there could be a tendency for them to stay too wet for the plants but this will be totally dependent on the type of coir used. Some coir is basically a powder like peat and will stay very wet while other coir is more like fiber matting and other coir could be the shell chips so it is all quite variable. So see how it goes. I’ve used peat pellets right in the grow beds before and that was ok for some plants.
Okay, thanks. I’ll stop panicking. lol. This is supposedly pure coir, so I think I’m safe from chemicals. As far as being too wet, they’re in the “dry” upper section of the GB, so they’re not getting flooded. Hopefully they won’t wick up too much moisture, but that seems less of a danger. And it’s only a few. I’ve got 10 small net pots of coir in a 100 gallon GB. So any pH change would be entirely unnoticable.
Though it is the peat-like texture. Perhaps next time I should do my seed starting in something else. Hmmm. Thanks for discussing it with me!
Yea, at this point you just keep an eye on things and see what works well and try new things instead of what didn’t work so well.
For many types of plants I simply sprinkle the seeds in the grow beds. Some seeds land where they get some moisture and germinate and others just lay dormant till they get shifted enough to get moisture and germinate. Others might do nothing.
But when trying to get a tray full of microgreens or shoots to germinate, I find the coir in a tray seems to work quite well sitting on the capillary matting.
As to the shift in pH and tannins in my big system I actually am looking for help bringing the pH down and tinted water doesn’t bother me as long as I can still see the fish. In a system running a much lower pH, it might bear very regular pH testing to keep it from dropping too low.
how tall are the pea shoots when you cut them?
Between 4 and 12 inches.
I’ve played around with cap mat on the gravel. Found out lettuce really likes to sprout (and grow) in a crease in damp capillary mat. A piece that had its other end under the water inflow did best. Less impressive was another folded piece that had a low end tucked down in the gravel below the high water point. I think my water rose above the high water point too often for too long (how dare it?).
If anyone hasn’t tried radish sprouts, they should. It’s like a zingy bite of radish but without waiting to grow the whole thing…
I’m walking out there now to see what’s survived the 4th freezing (or already-frozen, the last couple) night in a row. 😎
[…] RE Ash Swimming pool conversion. I have seen their videos, and love them, I might not have the chickens right over the fish tank as they do, but they have some great ideas. I am getting some tips from a friend who has visited the grow power setup. Pea and Sunflower Shoots on aquaponics | Aquaponic Lynx LLC […]