Stocking Level

What type of filter did you select? There are many of us on here that stick to the internal filter option even when we have bigger/potentially better filters in place as we believe this is a more accurate measure.

I personally believe a tank at 90% stocking using this measure visually looks full.

The other way to calculate your stocking maximum would be by using nitrate test results. See how much your tank water nitrate goes up in a week and limit yourself to a certain value at a certain water change frequency that is manageable for you personally.

The concept of having a bigger filter = more fish is now rather outdated. I always use standard internal even if my internal filters are over rated for the tank size. I suppose externals do increase the tank volume a bit, by whatever the volume of the filter is, but that won't make much difference. I would recommend using standard internal whatever the filter.
The amount of filtration has nothing to do with the amount of fish we can keep provided that the filter in use is not so small it can't move the water round properly. It is the size and shape of the tank combined with the nature of the fish that determines how many fish we can have. The tank shape does influence stocking levels - as extremes, a tall thin cylindrical tank can hold less fish than a long shallow tank of the same volume.


Provided you do not go over 90% for your tank with a standard internal in the CC, the right amount of stocking is what you are happy with.

I found the last one dead a couple of weeks ago.

Checking my notebook, I moved 7 from my 50 litre tank to my 180 litre on 20 September 2016 when I sold the 50 litre. Of these, two were left from a batch bought 21 September 2015 and 5 from a batch bought 27 August 2016.
Of these 7, I have found 4 dead fish one at a time since I moved them and I have also found the odd bits of bone which could have been a cory or some other fish. There is a vague chance I do have one left but they are very hard to see amongst the wood in my tank.


I am another person who has never had much luck with pygmy cories, or habrosus cories either. I am now going to remove them from my signature  I won't get any more of them since I can't seem to keep them alive for more than a year or two, and my 180 litre is supposed to be a generally Asian themed tank now.