Monday staff from the ECOTRON fixed a small Herp Nursery Peltier-incubator for me, which took them about half an hour.
Apparently, the poor thing had been standing in very low temperatures for too long, and the continuous heating had destroyed the Peltier element which heats and cools the incubator. That turned out to be a small 4 x 4 centimeter plate. Impressive that this is the core of the machine.
I’ve borrowed this photograph from an online shop.
After some tests, I found out that the following trick helps to keep air humidity around eggs OK during storage and incubation. Eggs are often shipped and stored in small plastic bags with some peat. To avoid these drying out, I store them in a plastic container together with some additional bags as in the photo. The extra bags contain a pluck of filter material, which I mildly wet. The water seems to pass through the plastic to keep the peat and eggs in the other bags at an appropriate humidity.
Quiet winter nights are approaching. Not too much to do about the adults.
Meanwhile, I’ve got hundreds of small containers with peat and eggs and I definitely need to reduce the amount of space they take. So I’m gradually drying the peat, picking out the eggs, tossing most peat away and storing the eggs and some peat in small plastic bags in an incubator.
Peat is what we need, as substrate for the Austrolebias parents to lay their eggs. Instead of boiling it (which I sometimes do in a rice cooker), I just heat it for a few days in a tank in full sun. The peat sinks after warming up sufficiently, and I use it straight away.
Suddenly I got fed up with transferring peat from a box/bag into a small tank, adding water, putting all peat back in a bag/box afterward. I now hatch the fry straight in the box where their peat is stored in. One liter or 0.5 liter plastic take-away boxes are used for storage+hatching. I buy them in a Chinese supermarket, per 50 or 100. I add rainwater from a tank to the peat in the box. After one or two days, the fry (if there are any) are poured off into a different tank. Drying the peat for the next round: I close the lid again and put the tank on its side. All water usually drips out soon. I am contemplating to construct some sort of dam-net-rake which allows me to pour of all excess water quickly.
The incubation of killifish often occurs quite simply on a shelve in the fish room. Then one has limited control over the incubation temperature and thus incubation times can vary. With more constant incubation conditions predictability increases and it becomes easier to decide when to hatch what. This can be achieved by using incubators, but these can consume a lot of electricity. I’ve recently tried some incubators which use Peltier elements. I tried both large models such as the one on the photo and small ones (Herp Nursery II) sold for incubating reptile eggs. I’ve checked the temperatures inside with a datalogger. In a large professional model, the temperature (22 C) was extremely well controlled. In the small ones, I found a temperature gradient from top to bottom. That was no problem, as it remained stable.
Small Peltier incubators consume (if the folder is correct) on average 10W per hour. They can run on 12V DC, meaning it would be feasible to power them by means of a solar panel also.
I use incubators systematically, and after this positive experience, I am replacing incubators by Peltier models whenever possible.