If I use alum to filter water for my pond will it harm my oscars?

Answer 1

I agree with the others - not a good idea. If your pond is in an area where it gets acid precipitation or there are acid-producing sandstones or shale in the pond, aluminum from the alum becomes deadly to fish if the pH gets to around 5.0.

http://www.cnr.vt.edu/extension/fiw/fisheries/pondslakes/interpreting_pond_water_quality.htm#Aluminum:

Answer 2

NO dont do it !!!!
Love your pond , love your oscars.
HAppy pond works great to remove biological contaminates.
It reduces the BOD and will promote the bacteria tha treduces amonia. Works great. I use it in a waste water plant and it really does the job , the water coming oput of my plant is better than some city drinking water......
Happy Pond is the version for fish ponds, e-bac 2000 is the version sold in bulk for waste water plants. Sam Reynolds can hook you up. http://www.environmentalbacteriacorporation.com/page5.html

Answer 3

Aluminum Sulfate would definitely not be good for your oscars. If your pond is cloudy just keep doing go maintenance practices and it will clear on its own.