Semantic Drift

So, we all know not to use soap in aquariums - but does anyone know why? I tried some Google research, but got nothing, really. All of it was about using soap in treating injuries, and the pathophysiology of said injuries.

All I can figure is that it would inhibit respiration - if the soap got in their gills, the hydrophobic fatty acid should bond to the membranes of their gills, with the hydrophilic alkali facing outwards, thus blocking avenues for gas exchange. It could also be an osmotic pressure thing - freshwater fish, having internal fluids less dilute than their surroundings, gain water through their gills. Interfering with gill function could (possibly) cause solute concentrations to increase too fast to compensate.

Perhaps it's soap's role as a surfactant, reducing the water's surface tension? I've not taken enough chemistry or physiology to know what this'll really do to a fish. (I am stoked to be taking "NC Freshwater Fishes" this spring, though).


Anyway, just brainstorming. Any ideas? Articles?

sirdarksol

I believe that I have read that the removal of the surface tension affects the retention of gas dissolved in the water. I don't recall the source, however, so I don't know.
Soap sticks to nearly everything, so your idea regarding the bonding to the gills could very well be right. Soap also tears oils apart, and it could be that parts of fish's bodies need to be coated with a natural oil (similar to the "slime" that coats their scales).

Honestly, I'd guess it's a combination of these factors, and perhaps others.

Butterfly

Soap will remove their slime coat and inhibit their respiration I believe is teh reason not to get soap in the tank. Hand lotion is another no-no in the tank.
Carol