Sheepsnana, knowing that you think anything small (was it under 100L you said?) is 'cruelty', I think you remain objective about tank sizes since house sizes, budgets, fish preferences and all those things can dictate the size of tank you have, and I don't think saying start at 200L is very encouraging. It's all well and good to say you get problems with water parameters on little tanks but there are also many positives.