Saturday, August 29, 2009

Problems - Part 2 of 3

I want to describe a problem I had with one of the larger grow beds. When constructing the first grow bed I didn't really concern myself with the underneath support. I figured I would do that when I mounted it. With the second grow bed I made the support external to the bed and the mount because I didn't like the support for the first bed. It turns out that the support for the first bed was inadequate as I suspected.

After mounting the grow bed, I felt a little leery at filling it all the way up with rock, so I put about 8 inches and used that for a couple of weeks. It was holding up so I decided to put more rock in. As I did, I started to hear the crinking and crackling of the wood. Inspecting the bed I found that one of the screws on a support board had missed its mark in the center of a 2x4. I must have put the screw very close, too close, to the edge of the board and now it had popped out the side. Without this support the bed began to buckle, eventually snapping the the 2x4 and was endanger of total callapse.

I rushed to find anything to put under the grow bed to prevent it from collapsing. I temporarily put a series of 2x4's under many areas.

After banging in the 2x4's to push the grow bed bottom up there was still a little bit of a bow, as you can see by the photo. I drew a straight red line on the photo so you can more easily make it out.

Now I had to figure out what I was going to do for a perminant fix. Do I remove everything and rebuild it or can I salvage what I had? Of coarse I was going to try the easiest solution first. So I set out to salvage what I had by making support legs and cross beams with 4x4's.

Shown below in the photos, this is ultimately what I have done. In a year or two or three when I have to clean the bed out, I will redo the entire base. But for now, this will hold up nicely. Click to enlarge the photo for a better view.

Adjusting the Aeration

I have adjusted the new aerators to get better performance. Mostly I just put the outputs closer to the water surface with less angle.

Here you can see the shallow aerators.
They have a wider spray with more of an angle.
They don't penetrate the water more than about six inches.

Here you can see the deep injection.
They have more of a "Jet" than a spray.
These get down two to three feet below the water surface.
They also create deep circulation, which is very important for aeration.

Wednesday, August 26, 2009

Another Thought on Aeration

My methods of aeration described in my previous posts(Here and Here) on the subject were fine as far as aerating the water. What I didn't take into account was the water loss from being directed into the heated 100+ degree dry air. The water was evaporating so fast I was sure there had to be a leak. After searching for wet areas around the pond and not finding any, I came to the realization that there was only one explanation, the water was evaporating.

In extreme cases, you can lose up to a foot a month from evaporation. I was losing that much, without the extremes needed to cause such a rate. While it was hot, it wasn't that hot, and there was, practically, no wind to speak of. It had to be the sprinklers and sprayers directing fine mists of water into the hot, dry air. This seemed, to me, the only plausible explanation. So I tested my theory by removing the grow bed sprayers and directing the sprinklers into the pond, rather than the air. It worked. Evaporation was unnoticeable on a daily basis.

Well, I had to get aeration and I didn't want the extra cost and noise of running an air pump. So I looked back at the injection method, which I liked.

New Injection Aeration:

I now have the sprayers off of the grow beds and I removed the sprinklers at the pond surface. In their place I put injectors directly above the water surface to prevent any evaporation. The aeration is still as good or better with an evaporation rate of about 3 to 4 inches a month. They need a little adjusting, but here is an idea of what they are:

During the winter I can put the sprayers back on the grow beds easily enough without evap worries or problems. There might be concern for wind causing some over-spray during stormy winter months, I'll have to wait and see.

Meanwhile it's still 100 degrees outside and I'm looking forward to some cooler late fall days ahead. Not to mention the best holiday we have...Halloween!


Tuesday, August 04, 2009

Simple Overview

Here is a simple image of the system as it will be very soon.

I still have to fix the leak in the third grow bed before I can get everything running at full capacity. That will be my next focal point.

The second phase will incorporate rainwater storage and a sprinkler system that uses pond water to irrigate the yard.