"~Vicki ~" wrote in message
...
I did not say it was my math but info from a book. The original
parameters were for 11% or 22%. I just used the books info on 10 and
50%

I have always been a 50%er anyways.

Vicki

I know people who do 100% changes and because they do it often, it works.
Doing 50% will also work, if it's done at a frequency which would prevent
any significant build-up since the last change (IMO). The only problem
with these massive changes is when the interval gets too long, - such
that the difference in parameters now becomes stressful. It's also not
possible with freshly drawn well water. Letting the interval frequency
slide is not uncommon with new hobbyists, so 50% would become more
problematic for them. IMHO, if you can do 50% at short intervals, then
the short interval might preclude the requirement to do such a large
water change ;~)

Having said all that, I'm a firm believer that aquariums are like
preparing fine meals. There are many recipes to success.

NetMax