Weir Wonderings
 

Has anyone had any experience with small fish swimming over, or being
swept over, weirs? Do they generally tend to stay away from
unexpected fast-moving currents "into the unknown abyss", or do they
instead tend to like to play with "weir roulette"? I am specifically
thinking right now of mosquito fish, but if anyone has experience with
larger fish, that would be of interest to me as well.

Thank you very much,
David
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For email, please eeliminate the threee dubbel-ewes in:

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I have a few small zebra danios in my tank that occasionally go through the
overflow teeth and down into the sump. My biggest concern is if they end up
in the water return chamber and get too close to the return pump, I'll end
up with ground fish jetted back up into the display tank. So far so good
thgough. The morning role call has had everyone accounted for lately.

Justin

"David" wrote in message
...
Has anyone had any experience with small fish swimming over, or being
swept over, weirs? Do they generally tend to stay away from
unexpected fast-moving currents "into the unknown abyss", or do they
instead tend to like to play with "weir roulette"? I am specifically
thinking right now of mosquito fish, but if anyone has experience with
larger fish, that would be of interest to me as well.

Thank you very much,
David
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~
For email, please eeliminate the threee dubbel-ewes in:


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"David" wrote in message
...
Has anyone had any experience with small fish swimming over, or being
swept over, weirs? Do they generally tend to stay away from
unexpected fast-moving currents "into the unknown abyss", or do they
instead tend to like to play with "weir roulette"? I am specifically
thinking right now of mosquito fish, but if anyone has experience with
larger fish, that would be of interest to me as well.

Thank you very much,
David



what is a weir?

If you are talking about an overflow box for a trickle filter, small fish
get eaten by them all the time. You can put netting around it to help. I
use the blue bonded filter pads in mine. I cut them so that they can go
into the skimmer box and block the openings. An added benefit is all the
crap it catches that helps with the prefilter maintenance.

--

Margolis
http://web.archive.org/web/200302152...qs/AGQ2FAQ.htm
http://www.unrealtower.org/faq

On Wed, 23 Feb 2005 06:37:49 -0600, "Margolis"
wrote:

"David" wrote in message
.. .
Has anyone had any experience with small fish swimming over, or being
swept over, weirs? Do they generally tend to stay away from
unexpected fast-moving currents "into the unknown abyss", or do they
instead tend to like to play with "weir roulette"? I am specifically
thinking right now of mosquito fish, but if anyone has experience with
larger fish, that would be of interest to me as well.



what is a weir?

If you are talking about an overflow box for a trickle filter, small fish
get eaten by them all the time. You can put netting around it to help. I
use the blue bonded filter pads in mine. I cut them so that they can go
into the skimmer box and block the openings. An added benefit is all the
crap it catches that helps with the prefilter maintenance.

Hi Margolis, I think we are talking about generally the same kind of
thing. For me, a weir is like an overflow spillway on a dam, to limit
the height of the water's surface. Your description sounds like it
might be applicable to what I'm trying to do, but I cannot picture it.
Would you have a make and model of your filter and skimmer box, so
that I can look up a picture of it? Thank you.

Thanks Justin, Do you think this is a learning experience? (Yes, try
not to laugh, I'm serious g.) i.e., is this something that the
smarter ones tend to avoid after the first trip, or does one just have
to continually be catching them and returning them back upstairs?
(Obviously the ones that go thru the pump do miss out on the learning
experience...)

On Tue, 22 Feb 2005 21:25:49 -0600, "JUSTIN BOUCHER"
wrote:

I have a few small zebra danios in my tank that occasionally go through the
overflow teeth and down into the sump. My biggest concern is if they end up
in the water return chamber and get too close to the return pump, I'll end
up with ground fish jetted back up into the display tank. So far so good
thgough. The morning role call has had everyone accounted for lately.

Justin

"David" wrote in message
.. .
Has anyone had any experience with small fish swimming over, or being
swept over, weirs? Do they generally tend to stay away from
unexpected fast-moving currents "into the unknown abyss", or do they
instead tend to like to play with "weir roulette"? I am specifically
thinking right now of mosquito fish, but if anyone has experience with
larger fish, that would be of interest to me as well.

Thank you very much,
David

"David" wrote in message
...
On Wed, 23 Feb 2005 06:37:49 -0600, "Margolis"
Hi Margolis, I think we are talking about generally the same kind of
thing. For me, a weir is like an overflow spillway on a dam, to limit
the height of the water's surface. Your description sounds like it
might be applicable to what I'm trying to do, but I cannot picture it.
Would you have a make and model of your filter and skimmer box, so
that I can look up a picture of it? Thank you.



this isn't the filter I am using, but it is close enough for you to get the
general idea. It was the best I could find quickly with a decent shot of
the overflow skimmer and prefilter.

http://thump.net/640408/Amiracle_-_MaxiReefWetDry.jpg

--

Margolis
http://web.archive.org/web/200302152...qs/AGQ2FAQ.htm
http://www.unrealtower.org/faq

"David" wrote in message
...
Has anyone had any experience with small fish swimming over, or being
swept over, weirs? Do they generally tend to stay away from
unexpected fast-moving currents "into the unknown abyss", or do they
instead tend to like to play with "weir roulette"? I am specifically
thinking right now of mosquito fish, but if anyone has experience with
larger fish, that would be of interest to me as well.

Thank you very much,
David


Without a doubt, they play weir roulette. The extent varies by the size
of the water body (smaller=more jumps), the water conditions (bad=more
jumps), food conditions and if they see-feel-sense water or movement on
the other side of the weir. Think about salmon making their way upriver.
It's natural.
--
www.NetMax.tk

On Wed, 23 Feb 2005 09:59:25 -0600, "Margolis"
wrote:

this isn't the filter I am using, but it is close enough for you to get the
general idea. It was the best I could find quickly with a decent shot of
the overflow skimmer and prefilter.

http://thump.net/640408/Amiracle_-_MaxiReefWetDry.jpg


Thanks, Margolis. This certainly looks like a comprehensively
designed piece of equipment. But I guess I just don't have enough
familiarity with the technology to understand how it works from
looking at the picture. I have found the websites of several
retailers that sell it, but I can't seem to find the manufacturer's
site. If possible, I would like to locate a technical description
and/or diagram of its operation. Do you, (or does anyone else) know
where I might look? Thank you very much.

On Wed, 23 Feb 2005 19:11:42 -0700, David
wrote:

On Wed, 23 Feb 2005 09:59:25 -0600, "Margolis"
wrote:

this isn't the filter I am using, but it is close enough for you to get the
general idea. It was the best I could find quickly with a decent shot of
the overflow skimmer and prefilter.

http://thump.net/640408/Amiracle_-_MaxiReefWetDry.jpg


Thanks, Margolis. This certainly looks like a comprehensively
designed piece of equipment. But I guess I just don't have enough
familiarity with the technology to understand how it works from
looking at the picture. I have found the websites of several
retailers that sell it, but I can't seem to find the manufacturer's
site. If possible, I would like to locate a technical description
and/or diagram of its operation. Do you, (or does anyone else) know
where I might look? Thank you very much.

FYI, AquaticHouse Customer Svc. was kind enough to email a couple of
*.GIF diagrams to me, and I see how it works now. If anyone else is
interested, please let me know and I'll be happy to forward their
email to you...
Regards, David
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~
For email, please eeliminate the threee dubbel-ewes in:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~

On Wed, 23 Feb 2005 20:07:24 -0500, "NetMax"
wrote:

"David" wrote in message
.. .
Has anyone had any experience with small fish swimming over, or being
swept over, weirs? Do they generally tend to stay away from
unexpected fast-moving currents "into the unknown abyss", or do they
instead tend to like to play with "weir roulette"? I am specifically
thinking right now of mosquito fish, but if anyone has experience with
larger fish, that would be of interest to me as well.


Without a doubt, they play weir roulette. The extent varies by the size
of the water body (smaller=more jumps), the water conditions (bad=more
jumps), food conditions and if they see-feel-sense water or movement on
the other side of the weir. Think about salmon making their way upriver.
It's natural.

Well, that gives me a pretty good perspective. And it also tells me
that there aren't going to be any shortcuts. Your suggestion of a
matrix of decreasing grid sizes, preceding the weir(s), will provide
more positive control anyway -- when it's time to lower the
mosquitofish population, just remove the last grid screen and let them
find their way over the weir, into the next lower pool, and, alas, the
predators.

Building a filter box with a matrix of removable grid screens,
installed in front of the weirs, (and subsequent waterfalls), seems
like a pretty straightforward solution.

Again, thanks,
David