The top of the tube goes into the top of the fishtank and is only underwater by a few inches. The bottom of the tube also goes into the top of the fishtank but runs all the way to the bottom. As the water is heated by the sun, it rises and flows into the top of the fishtank. The other end of the tube brings in new cold water from the bottom of the tank. I do think it's helping a lot. But it's a little flimsy out there, so I'll butt it up against the fence and fasten it to that.
I put up new tomato cages, and the plants were extremely unhappy about being moved. They're recovering, but they're still pretty sulky:
I started some more seeds. I've got radish, carrots (small golf-ball size and shape), green onion, red romaine, arugula, cress, savoy cabbage:
On the other side I've added leeks and brussels sprouts. Also some June-harvest strawberry plants:
The chard is starting to green up nicely now that the pH balance is fixed. And the cilantro is recovering from its transplant and thinning. The cucumber plant is moved next to the tomato frame and is several inches high now (but is hiding behind the chard here):
And now for the fun/work stuff...
It's definitely time to expand. The tomato plants are too close together and are blocking the sun from the other half of the growbed. I've always known I'd need to put in more growbeds to balance the size of the fishtank, but considering how the tomato plants are jammed in there it looks like I'll need to do it sooner rather than later. I've got a 3-day weekend so it's just time to buckle down and do it.
The right side of the greenhouse (facing as I am in the above picture) is empty... except for the inevitable junk that seems to pile up in any open space - mostly leftover lumber and bricks and such. My plan is to do a row of half-barrels al la Travis Hughey's Barrelponics. I already have the barrels, so it's just a matter of contructing the frames, cutting the barrels in half, and doing the plumbing. Then I plan to move the tomatoes over to the half-barrels. I'm going to plumb these a bit differently than Travis does, as my goals are different. More about that later.
And while I'm at it, I want to build some strawberry towers to hang over the fishtank. I'll water them directly from the rear sump which means the solids will all be filtered out by then. This will clear more room in the growbed, and also provide additional aeration for the fish. Okay, I probably won't get those done this weekend. I'm already overbooked, I can tell. But it's on the "do when I can possibly face more work" list.
I've thought a lot about how to properly split the water between the big growbed and the barrels. Right now I'm running a 15 minute fast flood, followed by a 45 minute slow drain. But I think what I'll do is convert to a low-level constant flow system. For this style the water is always running through the bottom 1/3 or so of the media and is drawn up to the plants by the wicking action of the media itself. Of course this won't work with gravel, but I'm already running expanded clay and it's perfect for this. The other consideration for this system is the aeration. It needs to be *very* well aerated. And I've already got a bit of a problem there.
Currently I have a large air pump that runs into a horizontal PVC pipe from which 3 air lines drop into the fishtank. They each terminate in airstones about a foot from the bottom of the tank. This was the system as the prior owner built it. Unfortunately, if the tubes don't hang to precisely the same level (and they don't of course) they don't all receive airflow. So I've got 3 hanging airstones and only one of the bubbles. The solution would be to even the length of the tubes... and clearly I haven't done that yet. Now I've decided against doing it at all.
I'm instead going to put a manifold onto the air pump and run those air lines all the way down to the bottom of the fishtank - the way everyone else on the planet seems to do it. I'm even considering putting one line into the sump tank - or maybe one in each sump tank - to assist in bio-filtration.
I think between the better aeration from the pump, and the constant waterfalls going into each of the growbeds, that should add a lot of air. Each half-barrel will have its own spout raining into it, the big bed already has its punctured PVC tube raining into it, and the addition of the strawberry towers (when I get to that) will do even more. I don't think aeration should be a problem at all at that point.
Back to the barrel plumbing changes: since I'm going to run a constant flow to a known depth, I really just need an overflow at the right place in each half-barrel. As long as that overflow pipe isn't any narrower than the inflow pipe for the water, it should drain fast enough. So I'm considering 3/4" extending from the front of each. These will all plug into the side of one long 2" pipe that returns the water to the front sump (the same one the big bed drains into). In order to keep the overflow pipe clear, and make for easy maintenance, I'm going put a half-pipe vertically at the front of the barrel. Rather like the media guard I have in the big bed, but up against a wall instead of surrounding an upstand. I think I will use Travis's sewer pipe suggestion for this. It may need some modification to work vertically instead of horizontally - particularly since the bottom of it will be on a curved surface and I don't want media sneaking underneath - but I'll figure it out. Perhaps some mesh over the bottom or something.
It's going to be a busy weekend!
