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10 models to compare

What water depth does a protein skimmer need?

Operating depths differ. TUNZE DOC 9430 spans 100-240 mm; Comline DOC 9012 DC needs 255-285 mm.

DOC 9430 has a 360 mm square body and needs 600 mm service height above its 500 mm body.

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With no preferences selected: C-120 is one option to compare.

No hands-on testingMethod and sources

C-120 · first with a product link

Model / item: 79360
  • Body length: 178 mm.
  • Body width: 152 mm.
What to note:

Body height: 457 mm.

View at ESHOPPS

If you choose Up to 110 mm for body length, the first option with a product link becomes Comline® DOC Skimmer 9001.

10 models compared; 10 have a product-page link.

The picks

5 options to compare

Compare the details that matter to your setup.

An option to compare

C-120

Body length: 178 mm.

Model / item: 79360

Key details

  • Body width: 152 mm.

What to note

Body height: 457 mm.

Body length: 178 mmBody width: 152 mmBody height: 457 mm
See all 5 specs
Body length178 mm
Body width152 mm
Body height457 mm
Operating water depth, minimum165 mm
Operating water depth, maximum216 mm

5 of 5 specs available · source checked September 26, 2026 · Source ↗
ESHOPPS · Product page checked September 26, 2026

View at ESHOPPS
Body length: Up to 110 mm

Comline® DOC Skimmer 9001

Body length: 110 mm.

Model / item: 9001.000

Key details

  • Body width: 63 mm.

What to note

Body height: 215 mm.

Body length: 110 mmBody width: 63 mmBody height: 215 mm
See all 5 specs
Body length110 mm
Body width63 mm
Body height215 mm
Operating water depth, minimum135 mm
Operating water depth, maximum155 mm

5 of 5 specs available · source checked September 26, 2026 · Source ↗
TUNZE · Product page checked September 26, 2026

View at TUNZE
Also compare 3

Nano Skimmer

Body length: 114 mm.

Model / item: 32001

Key details

  • Body width: 76 mm.

What to note

Body height: 305 mm.

Body length: 114 mmBody width: 76 mmBody height: 305 mm
See all 5 specs
Body length114 mm
Body width76 mm
Body height305 mm
Operating water depth, minimum203 mm
Operating water depth, maximum203 mm

5 of 5 specs available · source checked September 26, 2026 · Source ↗
ESHOPPS · Product page checked September 26, 2026

View at ESHOPPS
Also compare 4

PSK-100H 2nd Generation

Body length: 227 mm.

Key details

  • Body width: 178 mm.

What to note

Not listed by the maker: operating water depth, minimum, operating water depth, maximum.

Body length: 227 mmBody width: 178 mmBody height: 584 mm
See all 5 specs
Body length227 mm
Body width178 mm
Body height584 mm
Operating water depth, minimumNot listed by the maker
Operating water depth, maximumNot listed by the maker

3 of 5 specs available · source checked September 26, 2026 · Source ↗
ESHOPPS · Product page checked September 26, 2026

View at ESHOPPS
Also compare 5

Comline® DOC Skimmer 9001 DC

Body width: 63 mm.

Model / item: 9001.001

Key details

  • Body length: 110 mm.

What to note

Body height: 215 mm.

Body length: 110 mmBody width: 63 mmBody height: 215 mm
See all 5 specs
Body length110 mm
Body width63 mm
Body height215 mm
Operating water depth, minimum135 mm
Operating water depth, maximum155 mm

5 of 5 specs available · source checked September 26, 2026 · Source ↗
TUNZE · Product page checked September 26, 2026

View at TUNZE

Comparing C-120 · Nano Skimmer

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The facts that differ

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0 identical specs shown. Details that do not apply to these models are omitted.

Published specification comparison
SpecC-120Model / item: 79360No preferences selected.Nano SkimmerModel / item: 32001No preferences selected.
Body length178 mm114 mm
Body width152 mm76 mm
Body height457 mm305 mm
Operating water depth, minimum165 mm203 mm
Operating water depth, maximum216 mm203 mm

C-120

Model / item: 79360

No preferences selected.

Body length
178 mm
Body width
152 mm
Body height
457 mm
Operating water depth, minimum
165 mm
Operating water depth, maximum
216 mm

Nano Skimmer

Model / item: 32001

No preferences selected.

Body length
114 mm
Body width
76 mm
Body height
305 mm
Operating water depth, minimum
203 mm
Operating water depth, maximum
203 mm

Nano Skimmer

View at ESHOPPS

Compare all 10 models

— = no verified listing yet. The published order is independent of links.

All models and their decision specs
ProductHow it comparesKey specCompareAction
C-120
Compared with Nano Skimmer: body length, 178 mm vs 114 mm.
Model / item: 79360		Body length: 178 mmView at ESHOPPS
Nano Skimmer
Compared with PSK-100H 2nd Generation: body length, 114 mm vs 227 mm.
Model / item: 32001		Body length: 114 mmView at ESHOPPS
PSK-100H 2nd Generation
Body length: 227 mm; Body width: 178 mm.
Body length: 227 mmView at ESHOPPS
Comline® DOC Skimmer 9001
Compared with Nano Skimmer: body length, 110 mm vs 114 mm.
Model / item: 9001.000		Body length: 110 mmView at TUNZE
Comline® DOC Skimmer 9001 DC
Compared with Nano Skimmer: body length, 110 mm vs 114 mm.
Model / item: 9001.001		Body length: 110 mmView at TUNZE
Comline® DOC Skimmer 9004
Compared with Nano Skimmer: body length, 110 mm vs 114 mm.
Model / item: 9004.000		Body length: 110 mmView at TUNZE
Comline® DOC Skimmer 9004 DC
Compared with Nano Skimmer: body length, 110 mm vs 114 mm.
Model / item: 9004.001		Body length: 110 mmView at TUNZE
C-120
Compared with Nano Skimmer: body length, 178 mm vs 114 mm.
Model / item: 79360
Body length: 178 mm
View at ESHOPPS
Nano Skimmer
Compared with PSK-100H 2nd Generation: body length, 114 mm vs 227 mm.
Model / item: 32001
Body length: 114 mm
View at ESHOPPS
PSK-100H 2nd Generation
Body length: 227 mm; Body width: 178 mm.
Body length: 227 mm
View at ESHOPPS
Comline® DOC Skimmer 9001
Compared with Nano Skimmer: body length, 110 mm vs 114 mm.
Model / item: 9001.000
Body length: 110 mm
View at TUNZE
Comline® DOC Skimmer 9001 DC
Compared with Nano Skimmer: body length, 110 mm vs 114 mm.
Model / item: 9001.001
Body length: 110 mm
View at TUNZE
Comline® DOC Skimmer 9004
Compared with Nano Skimmer: body length, 110 mm vs 114 mm.
Model / item: 9004.000
Body length: 110 mm
View at TUNZE
Comline® DOC Skimmer 9004 DC
Compared with Nano Skimmer: body length, 110 mm vs 114 mm.
Model / item: 9004.001
Body length: 110 mm
View at TUNZE
10 catalog models

How the comparison works

Your choices are compared with each model’s product details. A missing or conflicting value stays unknown and cannot satisfy a choice you select. The starting order helps you browse; it does not rate real-world performance.

Source dates appear with each link below. A source date does not confirm today's price or stock.

Finder methodologyReport a correction
Sources for all 10 models

Budget for the cup to come out above the skimmer

Body heights range from 215 to 584 mm. TUNZE’s compact Comline DOC options are 215 mm tall, while ESHOPPS’ hang-on PSK model is 584 mm tall. Body height is the starting measurement; collection-cup removal needs additional service space from the installation directions.

The compact Comline bodies have a 110 mm by 63 mm footprint, compared with 178 mm by 152 mm for ESHOPPS’ C-series model. Our comparison uses equipment dimensions without running skimmers in an aquarium, so smaller dimensions are not a judgment of waste-removal performance.

Use the paired operating depths for the same model

ESHOPPS’ Nano Skimmer specifies 203 mm for both minimum and maximum water depth. TUNZE’s compact Comline options specify 135 to 155 mm, while its larger Comline DC body specifies 255 to 285 mm. Body height is not a substitute for that operating-depth range.

Minimum-depth values exist for 9 skimmers and span 100 to 255 mm. Use the corresponding maximum from the same row when measuring your chamber. ESHOPPS’ hang-on PSK model has no resolved operating-depth pair here, so consult its installation instructions before deciding placement.

Before you buy

If the body fits my sump, will the skimmer fit?

Only the body is checked. Hoses, fittings, lifting the collection cup off and your hands all need room beyond it, and TUNZE's 9410 DC figures leave out its post-filter, so read the installation notes for your model.

Why does water depth matter?

Each maker gives the water depth its skimmer should run in, so compare it with the level in your sump or tank, which can be different from one sump chamber to the next. The two Comline 9001 versions want 135 to 155 mm and the 9004 pair 225 to 245 mm; ESHOPPS's Nano Skimmer names a single 203 mm.

Are they all sump skimmers?

No. ESHOPPS's PSK-100H hangs on the back of the tank, and its page gives no operating depth, so the room behind your tank is the space to plan.

Can I order all ten directly?

TUNZE's seven pages showed them in stock on September 26, 2026. ESHOPPS's pages give US prices and a Where to Buy link without a stock statement, so a dealer is where to look.