The Mooskubators

When I first started to take an interest in bryophytes, I didn’t want just to do what botanists generally seem to do with the specimens they collect: Dry and press them until no more life remains. I wanted to keep a “living herbarium”, a collection of, well, living specimens. In general, bryophytes need a humid and moderately tempered environment to thrive. For cultivation, this creates two problems to be solved, desiccation and the hot summers we tend to get now in Austria. When I started, desiccation was the bigger problem. Since bryophytes only assimilate when they are wet, it is imperative to keep them moist for a high production of biomass. My first tries at cultivation were inspired by Frahms “Biologie der Moose” (2001), simply some glass jars filled with acid washed gravel and the specimen on top. However, the bryophytes dried to quickly. Closing the lid trapped the humidity inside, but also the heat. The moist, hot and unmoved air spawned fungi basically overnight, and one specimen didn’t recover. Out of ideas I resigned to regularly watering my collection.

Mooskubator 1.0

My frustration with the jars grew, tending to the specimens was made difficult by their high walls. I chose to switch to rectangular petri dishes and a cubicle made from wood and acrylic. A cheap plant lamp from amazon provided light, a thermo/hygrometer removed the guessing. I was somewhat satisfied now, and well, it kept the cultures moist and alive.

Mooskubator by day	Mooskubator by night	Trying to cool the thing with ice. It failed

However, in the heat of summer temperatures inside reached up to 27, 28°C. For most species, temperatures above 25°C in moist conditions are quickly fatal. I tried cooling with ice, thought about active cooling using Peltier elements. Both proved to be impractical.

Mooskubator 1.5

Since the first Mooskubator reached max capacity I planed an upgrade. An what an upgrade it would have been, go big or go home! A cupboard on wheels, just small enough to fit through my door: 2 m tall, 1,6 m wide and 0,8 m deep. Five shelves, everyone with its own lights and a proper AC unit to keep the temperature below 20°C.

Well, it never was started. Calculations showed the frame alone would have weighted 25kg when made from expensive aluminium profiles. The cost of profiles, screws, AC, lights etc. would have broken the bank at about 600 €.

Mooskubator 2.0

The sensible Idea I rejected at the beginning of planning Mooskubator 1.5 was to simply use a cooler and put some lights in them. After some days of scouting on local ebay and willhaben.at I found a suitable offer. A bit smaller than I liked at 0,6x0,6x1,2 m, but hey. After a nerve wrecking ride through Vienna it was mine. I still owe my two helping colleagues some beer.

The first upgrade (Mooskubator 2.1) was a themo-electrical relay from amazon (Pymeter), which keeps the temperature between 16-18°C by switching the fridge on and off. It was needed since the fridge itself had a max temperature of 11-14°C, which imo was a bit too chilly. The population of thermometers and hygrometers was expanded from two to six, giving a better spatial resolution. A few weeks later it was upgraded (Mooskubator 2.2) with new white LED strips and a TC421 to control them. Sourcing LEDs which met my expectations was difficult. The ones I liked needed a constant current source which doesn’t seem to exist, another shop didn’t ship to Austria. Finally, I settled for different ones with a white spectrum, but more dissimilar to natural sunlight than the others (LUMITRONIX MaxLine 35 1090 neutral white 28cm/24V are the ones I bought). Power source is a LPV-60-24 from Meanwell. Setting up the cabling was not amusing. I never done something like that before, the cables were a tad to thick (2,5mm2) to fit snuggly, I had the wrong cable clamps, and the LED controller broke. The clamps and controller were replaced by better fitting ones and a timer switch (Mooskubator 2.3).

"Finished" cabling with the (as turned out) defective TC421	Mooskubator 2.2 by night. Looks goregous compared to the violett light

And that’s where its at currently. It is planned to replace the TC421 by a working one. I noticed desiccation became a problem again, despite wetting the cultures twice a day. I think about adding a humidifier controlled by a humidistat. Also, temperature inhomogeneities increased. The back sits at about 12°C, while the front is 18°C and more. Sometimes ice is seen at the back. Fans will be added in the future to increase circulation.

Btw, Mooskubator isn’t a typo. It’s a portmanteau from German “Moos” for “bryophytes” and “Inkubator” for “incubator”.