On Thu, 04 Aug 2005 07:51:43 -0700, Courageous
wrote:


Wouldn't these small critters like tiny chorus frogs, pollywogs and newts
get sucked into that bottom drain?

Possibly. It's a large pipe. It's 3600 GPH through a 4". If it's too much,
they'll end up living in the settling tank. :-)

C//
Hi Courageous,
I've been trying to think how to construct a rather large screen dome
to place over the BD to address this problem. ("Large" = reduced
suction per sq.in. = small critters (and fish) can escape more
easily); but screen grid still large enough to permit mulm to pass
thru.

Or perhaps concentric domes of decreasing grid sizes(?)

It's a difficult question isn't it? -- trying to solve two intertwined
but mutually exclusive problems at the same time!

Do you think it's worth experimenting?

I've been trying to think how to construct a rather large screen dome
to place over the BD to address this problem. ("Large" = reduced
suction per sq.in. = small critters (and fish) can escape more
easily); but screen grid still large enough to permit mulm to pass
thru.

Or perhaps concentric domes of decreasing grid sizes(?)

Unnecessary complexity.

It's a difficult question isn't it? -- trying to solve two intertwined
but mutually exclusive problems at the same time!

Do you think it's worth experimenting?

Sure. Why not?

I think that you might start with:

1. Perforated PVC sheet.
2. An ability to draw a circle and cut it cleanly.
3. A dome (to place your hot pvc over, to form it)
4. A heat gun.
5. Elbow grease, safety precautions, and common sense.

I think you'll do fine, and the fabrication won't be as hard as you
think. Here's what you're looking for; it's probably expensive, and
if you hunt locally you'll be able to get it for less:

http://www.usplastic.com/catalog/pro...uct%5Fid=10081

Also, since you are thinking of novel screening solutions, you may
find this interesting:

http://www.aquaticeco.com/index.cfm/.../8559/cid/2079

Note that it is ever so slightly flexible (firm but somewhat soft). Not perfectly
rigid. It may get slighty deformed in shipping (mind did), but is easily straightened
with heat application (such as slipping it over 4" PVC and putting it in the sun).

C//

Courageous wrote:


Do you think it's worth experimenting?

Sure. Why not?

I think that you might start with:

1. Perforated PVC sheet.

Oh? Thanks for that link - I've never seen this stuff but pre-perforated
PVC sheet would be really useful for a project I have in mind...

2. An ability to draw a circle and cut it cleanly.

Uh-oh! That leaves me out :-)
--
derek

On Thu, 04 Aug 2005 19:02:20 -0700, Courageous
wrote:


I've been trying to think how to construct a rather large screen dome
to place over the BD to address this problem. ("Large" = reduced
suction per sq.in. = small critters (and fish) can escape more
easily); but screen grid still large enough to permit mulm to pass
thru.

It's a difficult question isn't it? -- trying to solve two intertwined
but mutually exclusive problems at the same time!

Do you think it's worth experimenting?

Sure. Why not?

I think that you might start with:

1. Perforated PVC sheet.
2. An ability to draw a circle and cut it cleanly.
3. A dome (to place your hot pvc over, to form it)
4. A heat gun.
5. Elbow grease, safety precautions, and common sense.

I think you'll do fine, and the fabrication won't be as hard as you
think. Here's what you're looking for; it's probably expensive, and
if you hunt locally you'll be able to get it for less:

http://www.usplastic.com/catalog/pro...uct%5Fid=10081

Also, since you are thinking of novel screening solutions, you may
find this interesting:

http://www.aquaticeco.com/index.cfm/.../8559/cid/2079

Note that it is ever so slightly flexible (firm but somewhat soft). Not perfectly
rigid. It may get slighty deformed in shipping (mind did), but is easily straightened
with heat application (such as slipping it over 4" PVC and putting it in the sun).

Thanks C//,
In my mind's eye I have been looking for products like both of these!
And great ideas for fabrication!
David