Water filling

The weather was "fresh" in south western Norway on the late January day when I filled up the tanks. There had been a storm the day before, and I had snow, rain, sun and lots of wind. Waves the size of houses came crashing in from the ocean to the west. Luckily the fjord landscape here has natural harbors everywhere, so it is not a problem to find a nice calm place to moor a boat, or in my case, get water.

Catching copepods

The week after filling water I seeded with copepods. I first tried catching some in a sheltered area where I caught Temora longicornis last summer. But spring hadn't started there yet and the net was virtually empty. It was possible to get a very good catch of Calanus finmarchicus and Pseudocalanus elongata in a more exposed location though.

Copepod video

I recently bought a used Canon EOS 600D camera body to use with my Canon 60mm macro lens. So I have been playing with making macro video and still shots. Below you can see my photo setup and some pictures, and my first published aquarium video ever. I really hoped it would be possible to make a decent video. But unfortunately it was impossible to keep the copepods in the extremely narrow focus area of such a macro photgraphy setup. Anyway, even if the video isn't the best quality, I hope it may be interesting for some to see how these animals move and behave.

The filter

My filter has worked really well. Particularly when considering it is a first attempt. There are things that could have been done differently: It would probably be better if the ozone chamber had larger diameter and the carbon chamber smaller. There is a bit too much carbon in the chamber at any given time. It would be better to have a smaller amount and change more often. After a few weeks it can get clogged up and block the exit from the ozone chamber, causing overflow. So the carbon needs to be taken out and rinsed every second week. The constant flow feed system and valve for emptying the chamber have been real blessings. The filter wouldn't be practically usable without those two. All brown coloring of the water is gone. There is hardly any protein film on the surface either. About 150 liters pass through the filter per day. The feed pump runs 6 times per day, 15 minutes each time. It has a 25 micron filter bag over the intake to prevent animals from entering. The ozone generator runs at max when the feed pump is on and is off otherwise.

Results

At the time of writing the system has been running for 6 weeks, 5 of them with copepods in it. Unfortunately the result is exactly like last time. The adults die at a slow rate while no nauplii appear. So no reproduction. This time I didn't introduce benthic copepods. Since the same thing happens now I can at least rule out that the problem was caused by the benthic copepods eating the eggs. Cannibalization or predation can of course still be the problem.

The phytoplankton aquarium has been doing very well though. I must admit I did several changes in addition to the filter. I switched off the cooling and let it run at room temperature. Since I didn't see any improvements with cooling, why not just let the bioprocesses run at full speed? There is a 25 micron nylon mesh on the feed pump intake. I adjusted the air bubbling up. I think I saw an improvement after that, so I have ordered another air pump and will experiment with that. I also want to start experimenting with CO2 dosing again to fine tune the phytoplankton production.

Plans ahead

I am starting to get ready to give up the zooplankton project for now. I will probably let it run over the summer though, since I won't have time to start anything new before autumn at the earliest. Right now I am toying with the idea of starting a shallow water algae aquarium again, like the one I had from 2007 to 2009. This time I would connect a phytoplankton refugium to it. The nutrients from the refugium would fertilize both microalgae and macroalgae. Plus it would be possible to keep clams, sea squirts, Henricia sea stars, and perhaps other filter feeders. The main goal of this project now is to practice how to run the phytoplankton refugium. Clams need a lot of food so it will be important to be able to scale the production to the demand. I have planned the new shallow water setup in the room where the current setup is. It will be about 600 liters. I could use my current phytoplankton refugium, the filter, the chiller (hope it is big enough), and a new DIY T5 lighting fixture. The only problem is the wave flow needed. It is absolutely necessary to get a very good gyre flow to simulate large, slow, waves that are strong enough to move a dense mass of kelp and other macro algae. To do that, as many as 4 gyre pumps, controlled by an aquarium computer, may be needed. The cost of that is an arm and a leg! But I think it's worth it! I recently developed an algorithm for the perfect wave setup simulating seasons. I would probably have to build my own computer to implement that algorithm, which I won't do (would take at least a year to build), but with an ordinary aquarium computer I could at least do something acceptable.