May 032021
 

The boxes have evolved again. I extended one to 600mm high so I can move the light further away to test levels a bit. Also got some coroplast and lined them with aluminum foil for the side panels but still using pizza box cardboard for the top.

I also got a peristaltic pump to test moving fluid around because I think the main problem I’m having is the water is too stagnant. At some point I read that duckweed likes stagnant water, but I think ‘stagnant’ in nature is still a lot more dynamic than a gallon of water in a pan in a box my kitchen. So I’m trying to figure out how to move nutrients around and keep the surface from filming up without disturbing the wolffia too much.

I’ve got a really rudimentary filter system with an acrylic pipe hanging from the basin in the water so I can drop in a tube to pump water from the bottom without sucking anything up from the surface layer. If I stir the water up a little it slowly pulls any algae to the tube and I can pull it up. That seems to be helping keep the algae growth a little bit in check but I need to make a less manual system.

The ‘sugar press mud’ trials have been interesting if not productive. I don’t think it provides enough nutrition for wolffia alone with or without light. But mixed with a little regular dirt it seems to increase growth above just regular dirt. Unfortunately the growth it increases is more than just the wolffia. It turns things into an algae soup faster than regular dirt and kills off the wolffia.

That seems to be the big trick here- limiting algae growth to give the wolffia a chance because everything I do do far that helps the wolffia helps algae a lot more.

I also tried a different species of duckweed called ‘Lemna Minor’ just because. It’s not ‘mixotrophic’ and doesn’t really fit my whole ‘space grits’ concept but I’m still just throwing stuff at the wall to see what sticks. I don’t think I like Lemna Minor much so I think I’ll try to find another wolffia variant to play with rather than a whole other species.

I think the next phase of this will be all about not growing algae, which if funny to me considering I wanted to grow algae before wolffia, but this experience is reinforcing the apprehension that kept from actually doing it. Algae is insane. I’m starting to wonder if I should get some little aquarium shrimp because apparently they help with that. I’d rather not because I’ll probably kill them and I want to learn to grow wolffia without critter assistance, but the more I read the more I think that’s probably the way to go at least until I get a better grip on what I’m doing.

Also I’ve moved away from my earlier obsession with time-lapses and microscopy. If I need to keep the water moving to grow them I’ll never get useful time-lapses so I need to rethink my ideas about using computer vision to characterize growth. I’d like to say I could try to ‘train’ a neural network to visually extract growth information from video, but if I was ever smart enough to figure that out I’m way too lazy now.

I have to give a nod to MakersLED t-slot LED heatsink housings. It just comes with the sink parts and fan, you supply the LED, power, and wiring. Really decent little kit here and works great with the 80/20 frame. I put a little thermal paste on, screwed down a COB LED, wired in an AC-DC converter for the fan and voila- a nice, modular little LED lamp and I can swap in whatever chip I want. I like these a lot. I got two of them running 50W LEDs.

Apr 022021
 

So this is a bucket of ‘sugar press mud’ or ‘belt press mud’. Provided courtesy of Louisiana Sugar Refinery in Gramercy, LA. They also provided a PDF with a chemical analysis but I’m not sure if it’s okay to post that and nobody but me reads this anyway so I didn’t.

It’s a byproduct of sugar cane processing. My understanding is it’s what came from bagasse but just wasn’t awesome enough to become molasses. It looks, smells, and sounds indistinguishable from dirt. I haven’t tasted it but I can guess. It feels almost like very rich topsoil, but disturbingly sticky. Like dirt sprayed with watered down syrup. My keen scientific intuition tells me that is probably related to the fact that sugary things tend to be sticky and this is made from the thing that makes sugary things sugary.

The first thing I did was roll up a little ball of it an drop it in a watermeal jar. I admit I was slightly disappointed it didn’t immediately overflow with watermeal growth like mentos and diet coke, but if it actually had that would have been weirder. It does roll up pretty nicely- kind of of a crumbly, semi-chunky dough.

So this is short post because I have no idea what’s next with this stuff. I’m not really in control, some force is making me want to grow watermeal and it made me think sugar press mud was how to do it so I got some. Weirdest psychosis ever, but it’s pretty innocuous and distracts me from the old familiar ‘existential paralysis’ brand of psychosis so I’m just going with it.

I’ll probably freeze some because it’s definitely going to become a fungus\mold extravaganza soon. I’m not really into growing mushrooms but I can’t help but wonder if there’s an opportunity there too. But unless\until some force makes me want to grow mushrooms too I’ll just keep wondering.