Plancton net material comparison

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MicroBob
Posts: 1279
Joined: Sun Dec 25, 2016 9:11 am

Plancton net material comparison

#1 Post by MicroBob » Tue Aug 13, 2019 7:33 pm

Hi together,
I ordered some plancton net material from Aliexpress and compared it to my two existing nets when it arrived: https://www.aliexpress.com/store/group/ ... 235aP9wwv4
The nets are all made diferently, from diferent diameter material and differently woven. The fine Net from Aliexpress has double strands in one direction. this will limit the water flow to some degree, but make the net stronger and better to sew.
If one is the master of the sewing needle it would be a good idea to make the last 50mm of net before the beaker from fine mesh to reduce loss of fine plancton when it is washed into th beaker at the end of the pull. But this would make it more difficult to sew.

I often weld plastics in bigger diameters. It might be an idea to weld the nets, but it would be timme consuming to develop the right process for this.

Picture with a tiny peak measuring microscope, calibrated with an object micrometer.

Bob

Aliexpress 280 mesh 50µ
75 pixel x 130 pixel
36µ x 63µ

Aliexpress 100 mesh 150µ
400 pixel x 400 pixel
193µ x 193µ

Bob's big net
200 pixel x 200 pixel
96µ x 96µ

Bob's small Kosmos-Net
180 pixel x 180 pixel
87µ x 87µ
Attachments
Aliexpress 280 50µ 1.jpg
Aliexpress 280 50µ 1.jpg (186.55 KiB) Viewed 321 times
Aliexpress 100mesh 150µ 1.jpg
Aliexpress 100mesh 150µ 1.jpg (138.75 KiB) Viewed 321 times
Bobs Netz groß1.jpg
Bobs Netz groß1.jpg (188.44 KiB) Viewed 321 times
Bobs Kosmos-Netz 90µ 1.jpg
Bobs Kosmos-Netz 90µ 1.jpg (156.15 KiB) Viewed 321 times

MichaelG.
Posts: 1393
Joined: Mon Apr 10, 2017 8:24 am
Location: NorthWest England

Re: Plancton net material comparison

#2 Post by MichaelG. » Tue Aug 13, 2019 8:14 pm

What an interesting comparison, Bob ... Thanks for sharing the photos

All are O.K.for the purpose, I guess; but they wouldn't make very good 'grading sieves'

MichaelG.
Too many 'projects'

Hobbyst46
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Joined: Mon Aug 21, 2017 9:02 pm

Re: Plancton net material comparison

#3 Post by Hobbyst46 » Tue Aug 13, 2019 8:45 pm

I have had some weight added to my plankton nets. Got the string that is used to pull long window/wall drapes down. It is sort of cloth tube, filled with small lead lumps. Three meters, that is ~100g, were added to each net. They were expertly sewn around the openings and along the net (see the thick white "strips").

The plastic neck of a large disposable soda bottle is "cuffed" within the small opening of the net (right side of the photo). The original plastic lid is piggybacked to the lid of a cheap plastic jar, volume ~100ml, on the right end of the net. The white stuff is Super-7 silicone adhesive that makes the piggyback.

Top net is a 120um hole size net (from the same Aliexpress), bottom net is 25um hole size net.
The efficiency of the added weight, and of the net itself, is still to be seen.
Attachments
Untested plankton nets.jpg
Untested plankton nets.jpg (109.68 KiB) Viewed 310 times
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

MicroBob
Posts: 1279
Joined: Sun Dec 25, 2016 9:11 am

Re: Plancton net material comparison

#4 Post by MicroBob » Tue Aug 13, 2019 9:05 pm

Hi Michael,
the middle two materials offer quite regular mesh sizes. I like stainless steel mesh better for sieves: Stronger, more precise, easy to weld to a ring and easy to clean.

These nets can probably cause trouble when you sample in sensitive environments since they tend to keep part of the catch in storage and transfer it from pond to pond. I think I will become a millionaire now with a plancton net fixative and deo combination! :lol: My two nets could use it for sure.

@Doron: Thank you for showing your nets - they look very expertly made!
How did you get along with the sewing? I work with lots of materials but am still uncomfortable with cloth and sewing.

The cone angle depends on the free mesh hole surface of the net (and the intended pull ing speed). For a coarse mesh the cone angle can be steeper.

The coarse mesh I ordered will probably be used for the filtration of our inflatable pool in the garden.

Bob

Hobbyst46
Posts: 2024
Joined: Mon Aug 21, 2017 9:02 pm

Re: Plancton net material comparison

#5 Post by Hobbyst46 » Tue Aug 13, 2019 9:28 pm

Naturally, sewing was done by needle masters, not me...some sewing machine work, some hand sewing... like they did before everything was done by robots and software...
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

MichaelG.
Posts: 1393
Joined: Mon Apr 10, 2017 8:24 am
Location: NorthWest England

Re: Plancton net material comparison

#6 Post by MichaelG. » Tue Aug 13, 2019 9:40 pm

MicroBob wrote:Hi Michael,
the middle two materials offer quite regular mesh sizes.

Bob
Sorry ... Yes, I should have been more specific

MichaelG.
Too many 'projects'

Hobbyst46
Posts: 2024
Joined: Mon Aug 21, 2017 9:02 pm

Re: Plancton net material comparison

#7 Post by Hobbyst46 » Thu Aug 15, 2019 10:32 am

Hobbyst46 wrote:I have had some weight added to my plankton nets... ~100g were added to each net...
The efficiency of the added weight, and of the net itself, is still to be seen.
Update: the nets were pulled in seawater near the shore. They sank easily into the water and collected organisms as hoped.
Warning: the yield can become foul-smelling within hours.
Zeiss Standard GFL+Canon EOS-M10, Olympus VMZ stereo

MicroBob
Posts: 1279
Joined: Sun Dec 25, 2016 9:11 am

Re: Plancton net material comparison

#8 Post by MicroBob » Thu Aug 15, 2019 2:46 pm

I like your idea with the lead - tape. This solves the problem to apply weight in well spread manner to the sensitive mesh.

MicroBob
Posts: 1279
Joined: Sun Dec 25, 2016 9:11 am

Re: Plancton net material comparison

#9 Post by MicroBob » Fri Aug 16, 2019 11:09 am

Hi together,

for comparison I show here a picture of the stainless steel mesh I like to use. It is either 25µ or 50µ.
Compared to the plastic fibre net material it is more precisely woven and quite robust.

Bob
Attachments
Edelstahlgitter Auflicht klein.jpg
Edelstahlgitter Auflicht klein.jpg (484.11 KiB) Viewed 188 times

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75RR
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Location: Estepona

Re: Plancton net material comparison

#10 Post by 75RR » Fri Aug 16, 2019 12:57 pm

That does look robust. Useful not only in that it will doubtless last longer, but also in that it can be more thoroughly cleaned.

Would not think one would want old dead/decomposing matter mixed in with the new samples.
Zeiss Standard WL (somewhat fashion challenged) & Wild M8
Olympus E-P2 (Micro Four Thirds Camera)

MicroBob
Posts: 1279
Joined: Sun Dec 25, 2016 9:11 am

Re: Plancton net material comparison

#11 Post by MicroBob » Fri Aug 16, 2019 4:10 pm

For a conical net the material is a bit expensive, but for filters made from plastic tubes and stainless mesh it is ideal. The mesh can simply be welded onto the tube with any piece of metal that has more than the melting temperature of the plastic. For plancton fishing one can just pour 20 beakers of water through the filter and then store the filter in the beaker, the bottle in the filter, and all together takes up little space in the backpack.

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