Optimum flow rate through filter.

Brendan wrote:
The pond is the "Eagle" design from the lotus toughline range with a
capacity of 1725 litres (455 US gallons).
We like to see and hear a lot of water on our waterfall, and we also want
to see oxygen entering the water. We have a substantial pump capable of 6000
litres/hour !(1583 USGals/h)

(The Pump is the Laguna Max-Flo 1500/6000)

We also have a filter (with UV) which is suitable for ponds up to 3000litres
(791 US Gallons)

(It is the Green 2 Clean 3000 by Oasis).

I agree that the pump is way too much to flow through the filter, so I have
fitted a T-piece in the hose from the pump with a controlable tap between
the T-piece and the filter. The other output from the T-piece flows back
in to the pond via waterfall bypassing the filter and tap. This T-piece
principle avoids unnecessary strain on the pump.

I can measure the flow of water through the filter by collecting the water
coming out of the filter in to a measured bucket, timing how long it takes
to fill the bucket.

So, you can guess my question...
What is the optimum rate of water to flow through my filter?

This should be in the owner's manual. My guess is 791gallons/hour, if it is
rated for a 791 gallon pond.

What is the general guideline in coming to your answer?

A lot depends on pond size and residents within. The smaller the pond the
more you have to treat it like a large aquarium. Anything under 500 gallons
here in the states is considered an aquarium, so once to twice per hour
isn't unusual. Over 5,000 gallons the flow is often less than once/hour.
Serious show koi people turn their ponds over 1/hour regardless of size.

We have about 15 adult goldfish and about 30 baby-fish

And I'd kind of put that on the upper end of the stocking rate, so I'd
definitely want it turned over 1/hour, imo.

My research has shown conflicting answers.. Some quoting "1 pond-volume of
water every 2 hours", others saying "2 pond-volumes of water every hour"

That's ponding for you. ;-) The above can all be correct, based on size of
pond, size of filter and residents within. ~ jan

--------------
See my ponds and filter design:
www.jjspond.us

~Keep 'em Wet!~
Tri-Cities WA Zone 7a
To e-mail see website

My research has shown conflicting answers.. Some quoting "1 pond-volume
of
water every 2 hours", others saying "2 pond-volumes of water every hour"



That's ponding for you. ;-) The above can all be correct, based on size of
pond, size of filter and residents within. ~ jan


Is there anything wrong in adjusting the flow to the maximum rate that the
filter can handle even if it exceeds the recommendation?

In other words, is too much filtration a bad thing?

Brendan DJ Murphy wrote:

My research has shown conflicting answers.. Some quoting "1 pond-volume
of
water every 2 hours", others saying "2 pond-volumes of water every hour"

That's ponding for you. ;-) The above can all be correct, based on size
of pond, size of filter and residents within. ~ jan


Is there anything wrong in adjusting the flow to the maximum rate that the
filter can handle even if it exceeds the recommendation?

In other words, is too much filtration a bad thing?

The key is "...the filter can handle...". Providing that the filter really
handles it, it doesn't make much difference, but figuring out exactly what
the filter can handle is tricky. Too much flow encourages channeling -
where the water manages to bypass most of the filter medium. Too little
flow can mean that the filter actually isn't working up to its capacity.
So, as fast as it can handle without channeling is good, but identifying
channeling is difficult.
--
derek

Is there anything wrong in adjusting the flow to the maximum rate that the
filter can handle even if it exceeds the recommendation?

In other words, is too much filtration a bad thing?

The key is "...the filter can handle...". Providing that the filter really
handles it, it doesn't make much difference, but figuring out exactly what
the filter can handle is tricky. Too much flow encourages channeling -
where the water manages to bypass most of the filter medium. Too little
flow can mean that the filter actually isn't working up to its capacity.
So, as fast as it can handle without channeling is good, but identifying
channeling is difficult. Derek

One of the ways one can identify channeling is murkiness in the water that
wasn't there prior to turning the flow up. Water quality, by testing the
water may be another.

In my system (at the Demon. Pond) channeling in the pre-filter causes the
bio-filter pads to clog faster. We fixed that this year by cleaning the
pre-filter every 4 weeks no matter what, and it helped that we secured the
bio-pads with hardware cloth (wire mesh) so they couldn't collapse when
they got muck on them. The bio-filter is horizontal flow so we could spray
the muck off the front pad as long as it didn't collapse. Turned out, only
the first pre-filter cleaning, which had to go longer than the 4 weeks, we
did have to spray that front pad off. After that, it wasn't a problem.

At home, I don't have this problem at all, I only clean the prefilter 4
times/year and it runs 24/7 all year long. Fish load is surely similar, the
D.pond has more fish, but they're tiny in comparison to what I have at
home. Pound for pound I may actually have more fish.

Long story, short answer, I don't think there has ever been a case of too
much filtration, but blowing by the filter, as Derek mentioned via
channeling, doesn't count. ;-) ~ jan

--------------
See my ponds and filter design and the Demon Pond:
www.jjspond.us

~Keep 'em Wet!~
Tri-Cities WA Zone 7a
To e-mail see website