The process of moving the tank over took about four hours in total, with the help of two other people.
We started by switching off the heater in the old aquarium, so that it had time to cool down before we drained the water and adding a small amount of dechlorinated water into the new aquarium so that the substrate was easier to spread.
The next step was to switch the filter off and pull up the plants in the old aquarium, placing them in a bucket for later.
At this point, one of my helpers discovered a log full of pleco fry, who decided to pick that moment to leave the log. Catching them out was probably the most time consuming part of the whole process, in the end. We managed to get most of them moved to the grow out aquarium, but a few which got into the plants ended up going straight into the new aquarium.
I found that the easiest way of moving 50kg of Dennerle’s quartz gravel is to syphon it out of the aquarium, into a bucket, with the water. We decided to move most of the gravel before starting on the fish, so that we would not harm them with the gravel.
Once the gravel was moved over, we caught the fish out and moved them into the new aquarium, which was by now half full of water from the old aquarium. All in all, there were four adult keyholes (two from a different aquarium, because of aggression), six blue rams, 18 harlequin rasboras, five bristlenose plecos (and fry), one mustard spot panaque, one rusty pleco and five dayi gouramis.
The rest of the old aquarium water and new (warm) dechlorinated tap water followed.
Once the aquarium was full, we tipped the plants in (it being too late in the evening to do the actual planting), added the heater and filter, then started the filter up. I only had one of my 200 W visitherms around, but that was good enough for the job in the short term. I also found that I would need new tubes for the external filter.
We left the new aquarium to settle for the night at 22 °C, 6 °KH, 20-22 °GH, ammonia and nitrite at 0 ppm, nitrate at under 5 ppm and pH of 7.0.