Willem Velthoven

Disaster Strikes

Power outage kills babies while oysters fruit

Last thursday our 1000 catfish fingerlings arrived and now two of our towers are inhabited by the little creatures. In the night of saturday22—sunday23 there was a power outage. More than 250 baby catfish died of oxigen shortage. All other fish seem to be OK

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bucket_of_catfish - The 271 dead baby catfish in a bucket.

They all survived the trip from Obervolkach. Johan, Tyler and Willem put them in tower 1 and 2. On friday afternoon we checked them and they were fine.

And on sunday afternoon Johan, Wendy and Willem found them almost dead.

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Power outage graph december 2012 - This isn the light monitor of tower 1. Normally the light switches off at about 12 and on again 6am. At 5:30 the line becomes dotted – sign of no data – because the power goes off. Power switches on at 13:30


The power outage lasted from 5:30 till about 13:20.

A quarter of the catfish population in towers one and two died.

When we arrived it even looked worse, the fish were at the surface trying to get air. After restoring water and air circulation many of them started to swim around again.

On monday morning, one day after the accident, the surviving fish were happily swimming around in their basins. No further casualties.

The fish in towers 3 and 4 seemed unaffected. These towers have lower fish density which probably explains that they were not running out of oxygen so fast. Even the trout seemed fine.

What shall we do to prevent such disaster in the future?

On a positive note, the oyster mushrooms are fruiting in the Aquaponics tent. We've put them there so their mycelium can provide CO2 to our plants. After 5 weeks the mycelium is peeping trough the little ventilation holes and massively producing mushrooms. On sunday we harvested 4 kilos!