"Harry Muscle" wrote in message
...
"Paul" wrote in message
...

Harry Muscle wrote in message ...
I started playing around with my Fluval 404 in preparation for
getting my
55G planted tank finally setup. I have a bunch of plumbing
connected to
it
(partly base tmax's design) and according to my
calculations/tests
I
have a flow rate of around 130gph (down from the 225gph with nothing
connected).

First I'm wondering if this is enough filtration. I'm planning on
this
being a medium planted tank with a medium to heavy fish load. I
know I
can
just add a HOB filter and be safe, but I would prefer to stay away
from
HOBs
if possible.

Second, I'm wondering if I will have enough current in this tank. I
know
it's hard to say without knowing exactly which fish I will have, but
I'm
hoping to get a mix, some that like current, some that might not.
So
would
130gph provide enough current for your average planted community
tank or
should I consider adding a power head, and if so, how strong?

Thanks,
Harry



if I could give you one word of advise: do a physical test with a
measuring
container and a stop watch for your gph reading. it will be alot less
than
the mathematical estimate. you should turn your tank over at least 3
times
an hour



I measured exactly how long it took for a bunch of bubbles to travel
from
the filter to the outlet, I then did the math to figure out how much
water
volume is in the pipes between the filter and the outlet and then
converted
all of this to gph. I know that measuring the speed of bubbles isn't
the
best way to figure out gph, since they don't always travel at the exact
same
speed as the water around them, but it's a pretty close estimate. And
since
my outlet is permanently plumbed into the tank with PVC pipes, it's way
easier to do this.

Harry


I'm not certain of the reliability or accuracy of your method. Can you
attach an extension hose to your filter output to feed a pail of water so
that you could then time the flow to get gph. Keep the end of the hose
at the same height as the level in your tank (replicate the head
pressure). Another method uses a large fish bag. With someone using a
stopwatch, slip a fishbag around the filter output (under water) and
partially fill the bag (do not overfill as you would introduce a
non-representative back-pressure). Stop the watch, remove the bag and
empty it into a container with graticules, and then do the math.

Doctrine has it that you need to do the tank volume so many times per
hour. Actually this is like the fish loading guidelines, more holes in
it than Swiss cheese ;~) For example, go to
http://www.2cah.com/netmax/basics/fi...ers.shtml#spog and scroll
up a few inches to a flow comparison (using manufacturer's specs) on 66
to 75g tanks. Before any losses due to detritus accumulation, the specs
range from x1.5 tank volumes per hour (Eheim) to x4 (Filsar). Did you
know that the spec for ponds is x0.5 per hour. There are many variables
at work, different elements of filtration work better at different
speeds, filter media efficiency, work sharing (plants), tank depth (to
prevent stratification), amount of breakwaters (rockwork, driftwood) etc
etc. Don't get too hung up on the numbers. While x3 is a very good
design reference point for canisters, it doesn't mean it will not work at
x2 or even lower. (jmo)
--
www.NetMax.tk