System overload

Guess I was too optimistic about how many fishes the aquarium could house. I have measured nitrate and phosphate a couple of times the last months and they were at a steady high despite using rowaphos  and reef pellets for removing nitrate. I have added a reactor chamber run by a small eheim pump (around 400  l/h), but it did not help much, nitrates where still around 2-4 mg/l and phosphate around 0,4 mg/l.

So last weekend I changed 600 liters of water and cleaned the sump and the upper filter aquarium. It also seems that the upper filter aquarium did acts as a filter as I hoped, so I removed some of the live rocks and placed them in the  sump. Now the upper aquariums acts as a crustacean zoo, with at least 4 species of crustaceans, to keep them from eating my snails and being eaten by the turbot.

The turbot by the way ate the  small lumpsucker after just one week. After the water change the nitrate  and phosphate is much lower, the big fishes are gone, so I hope that will help.

Here is a photo of the upper filter aquarium and one of the squatlobsters.

Full view of top filter aquarium 1,7 m longSquatlobsterReactor with quickphos phosphate remover
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The cod finally got to big for the aquarium – mostly because it eats more than the filters can handle. The two sculpins where put back into the ocean.

Instead I caught a lumpsucker, shrimps and thousands of mysis to feed the shark babies. I now have three newly hatched sharks and a small Greater weever.

Below are pictures form my collection trip when I caught the Greater weever and msyis caught during a night dive. Mysis gets attracted to the light form the dive torch and are easy to scoop up with fine-mesh net in front of the light.

Flatfish front onGreater weeverthe one-eyed-turbotJellyfishSaithe caught in a netGreater weeverCommon shore crab feasting on a dead sculpinCod and sculpins going back to the oceanGreater weever and shark side-by-sideMysis aka. cloud of food
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Aquarium final finish

The aquarium is finally done. I have been discussing the frames and hatches a lot with the carpenter and we ended up doing it in aluminium and acrylic plates. The plates are fixed to the wall with velcro glued and nailed to to wall. It think is looks great with a nice minimalistic touch. And most importantly it is easy to access the aquarium. Yesterday the two shark egg hatched so now there are two very small almost white sharks in the tank.

FrontFull tankFull tank from the sideBaby shark
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My tank has got new sharks small-spotted catshark (Scyliorhinus canicula). Sharks are my favourite fish, since they reaylle act and look like the predator they are and they seem to have a bit more personalty than the always hungry cods. Three eggs are waiting to hatch and one has already hatched. The hatched one likes to eat small herring and mysis, so for now it is growing fine.

Here is a photo of a shark embryo waiting to hatch. Its fine brushlike gills are clearly visible and the eyes is very large already.


Scyliorhinus canicula

Scyliorhinus canicula

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Småland – orchids and insects

This year I finally had the opportunity to travel to Sweden around “Midsommar” where the swedes celebrate the longest day of the year. This is also the best time to study orchids, since most of them is blooming. So we travelled to “Øland” an elongated island east of Kalmar. Øland is famous for its orchids and house several rare species, since most of the island is old limestone and grazed by cattle and sheep, which creates lots of habitats for the orchids. I was also lucky enough to see the European bee-eater, which is a rare guest so fra north. Up to 25 of them is breeding or staying in the area around the lighthouse at Ottenby in the southern-most part og the island.

123456778 Dactylorhiza maculata Heath Spotted Orchid9 Filipendula vulgaris Dropwort1011 Purple edged copper121314151617
Posted in Nature photos


This last week I had some really nice nature trips close to home. Springtime is beautiful in Denmark -plants are emerging, insects buzzing and toads croaking.

I har a trip to “Hellebæk Kohave” near Helsingør, “Allindelille Fredsskov” near Ringsted and “Kulsbjerg” near Vordingborg, which serves as a military exercise area. Hellebæk Kohave contains som very fine bogs with spaghnum mosses, sundew and cranberry. Allindelille Fredsskov is one of the few Danish forrest, which grow on old limestone deposits, which has developed a special flora with herbs that thrive in nutrient poor conditions and orchids. Kulsbjerg is one of the best places to see tree frogs.

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UW photo Norway – Wide angle

During our vacation we took a roadtrip north to Sveggvika south of Kristianssund from Bergen, on the way we visited Florø Rorbu. Both places where incredible. We lived in hotel rooms with free view to ocean and mountains. Att Sveggvika you even had White-tailed Eagle on the terasse.

Here are some photos of the underwater landscape with large kelp forest, wrecks and thousands of saithe (Pollachius virens).

Plumose anemone on a anchor chain



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UW photo Norway

My easter holiday was spent in Norway, and we were reallye lucky with the weather, so while my girlfriend sat on the rocks and knitted sweaters I went freediving.

It is a bit weird to go diving , when all others you meet are going skiing and and you are driving through snow-clad mountains on the way.

Norway mountain road

Norway mountain road between Bergen and Aalesund.

But when you are greeted by this view when you drive out from Bergen to the islands east of the city you hurry in to the water.

Panorama Turøy Norway

Panorama Turøy Norway

The tidepools are teeming with life, especially filterfeeders, snails, anemones, nudibranchs and billions of zooplanktonic copepods and jellyfish. Between the islands there are a constant current of water bringing food and later in the summer I have seen schools of herring feeding in the sound.

Beadlet anemone

Beadlet anemone sheltering in a crevice in the cliffs

Nudibranchs with eggs

Nudibranchs with eggs

 dahlia anemones

Dahlia anemones at the foot of the cliffs


Limpets feeding on algae on the cliffs

Jellyfish and copepod

Jellyfish and copepod

Topsnail and blue rayed limpet

Topsnail and blue rayed limpet feeding on algae and kelp.


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I hoped a lot of water would ease the problems with high nutrients, but I had a few deaths among the fishes and feeding the to much. So now the algae has taken over.  I changed half of the water in the aquarium, which reduced the N and P somewhat, but the rocks are still covered by red slimy algae. The next step will be to add a filter with phospate remover like Rowaphos. I´m still trying to work out how to build a nitrate reducing filter. Meanwhile I have added a small army of snails. Now I have chitons, limpets, flat periwinkles, edible periwinkles, topsnails and a few blue rayed limpets.

Here´s a photo of the front glass. A week after I introduced the snails the glass was cleaned.

Snail army

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the perfect food for the coldwater aquarium

On a diving trip too Sweden I stumbled upon the perfect food for the aquarium – tiny herring. They were sold in a supermarket as bait-fish. I have tried using white-fish bought from the aquarium stor before, but they apparently smell wrong, my fish does not react to them. But herring make them crazy. The cod ate 4 in 2 minutes!

Here is “Torben” as we call to most aggresive of my two cods after he swallowed his 4th herring:

cod feeding on hering

The sculpins where not as fast in getting to the herring, but when the hermit crabs started to move them around the sculpin moved in.

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