SG Talk

https://ezbuy.sg/product/11000001293833....ncentrator&baseGpid=11000001293833&pl=1&ezspm=1.20000000.22.0.7

shd be very good for fish tank.

They put hospital grade. I bought another brand on the way. These are only for 1 or 2 persons. It cannot be for the whole room because the discharge are in the same area unless there is a long pipe.

these quite cheap

Most of them are around these prices. 1 Ltr = 93%. As the ltrs increase the concentration drops.

More oxygen more youthful one look?

No idea.

too much o2 can cause damages to crll membrane, the brain and lung, and bubbles in blood stream.

can experiment by turning on max air supply to fish tank. very soon all fish would die