Why No Prob With Bare Concrete Tank In Backyard Options

[max]

goldfish keeping has become pretty complicated these days , remember cousin of mine used to have a concrete tank 8x3x2.5 cemeted to the floor in his backyard way back in Lorong Ah Soo kumpung days.

There isn't any need for filtration, it is just like throwing the fish in & it will survive. Left in the open you have green water, so green that you can't see the occupants at all not until it surface for food . I remember they is no Hikari or Tetra food, just humble white fish bread, only 0.30 cent. a package & the goldfish wahsay man puipui sweeswee one.

Water change is about once in every 2 months, no drainage system just the tradition way of removing all the fishes, scoop out the water & re-introduce the fish & bingo! .

Can anyone explain why such a method of fish keeping is possible those days & why can't it be the same today?

[CyberET]

I think there is one very important element ... environment.  The environment in the early 70s is pristine as in no human intervention, where now the water are treated, the pipes are treated even new water are recycled / created (not sure which word to use). 

Besides that the air is very different, the whole season thing is all wrong. 

So to some extend I think that have an impact.

The other I'm wondering if the strand which is in its continuous mutation made a difference.

yup