The reason I used Brown sugar is mostly just that that was what the DIY aquarists I know used.
From what I saw at the time, one of the benefits of the brown sugar was the slowness of the reaction, which allowed the same batch to work over the course of a couple of months.

Sorry for the lateness of my reply. The PH drop isn’t so bad; a lot of aquarists do planted tanks (tanks with plants as the showpieces, rather than the fish) and a lot of them use DIY CO2, like I’d done (that’s where I got the recipe). They experience drops in pH, but nothing too [...]

Also, I found one problem was success.
The plants at the top grew bigger, and their root systems held more water, and they used more water, so after a while significantly less water made it through to the bottom, and what did was clearly less nutrient-full than at the top.

Oh, also, I totally agree with Guppies. That’s a group that will scale up nutrient production as your plants scale up in size!

Sorry, Nate, I agree too. It’s inhumane to grow fish in such tight confines, unless they’re tiny fish and goldfish are not tiny. Since you’re using the term Aquaponics, in theory you’re going to harvest the fish too (long run, I know, but that’s what Aquaponics is about, otherwise it’s just hydroponics with fish poo, [...]

Can I make the suggestion that you try one column with the water heater and one without? I suspect you’ll end up with some problems with the heated water from temperature shock. Room temperature seems best to me, where the plant doesn’t suddenly have to adjust to a difference. Alternatively to a water heater, you [...]

I had decent results producing peas and lettuce with CFLs. I wrapped the whole thing in an reflective emergency blanket, for one, and then made sure I got CFLs that had a high enough spectrum of output. 6500 kelvin or higher is good. You can find more info about spectrum if you look into growing [...]

Oh, sorry, “pro” #2 for Clay – you can form it on your own safely, and can be to any specification you want.
Also, can be made extremely pretty.

Hey, I was thinking about this for a while too, and there’s a couple of non-glass options: 1) copper piping – pros – Already made for plumbing, made to pretty exacting standards, lots of parts available, also see last element in cons – cons – Leaches copper. Not in amounts that I would consider worse [...]

Beautiful!! Love the video! I’m coming to Malmo next week. Where do you guys live?

This is a great way to increase the water pressure without using a 4ft deep tank. Thanks for sharing! I had a similar idea, since I was using a 2′ deep fish tank raised 3 feet off the ground, and maintenance was a huge issue. In it (warning: untested) the waterline comes out of the [...]

Thanks for all your advice, guys. This really helped. We have now got the process worked out better and have also seen a lot of demographic trends over the last 6-8 months since we started selling kits and bottles. We are now selling kits with bottles pulled from the trash and prepared by the Mid-Hudson [...]