"DD DDD" wrote in message
...
I have a 300 gallon pond with a oversized filter and pump. (1800 gph)
While it keeps the water clear it also makes a lot of water movement. I
am going to waterfall it soon. I was told that shutting off the pump 1
hour twice a day would not kill the good bio bacteria. I need these 2
hours so I can feed my fish and turtles. I also was told by a petshop
that even 12 hours would not hurt the bio filter. What do you all think?
Thank you


The consensus in this group seems to be 4hrs is the upper limit, but a lot
of factors come into play, such as the size and design of the filter. If the
bio filter is tightly packed with material, a stop in water flow would cause
the bacteria in the bio filter to quickly consume the available oxygen. A
loosely packed filter with plenty of water would survive longer. It
shouldn't take you an 2 hours to feed the fish, they're usually done feeding
in a few minutes, unless you toss 1 pellet in the water at a time.

I run my pump for 12hrs a day, on two hours, off two hours,

-S