150 Litre Aquarium Skimmer Explained: A UK Buyer's Guide

Short answer: a 150 litre aquarium skimmer is a surface skimmer for a larger planted or community tank that clears the oily film off the top so the water stays clear under the light. Choose one sized for roughly 100 to 150 litres with a floating comb and adjustable flow, and treat the root cause of the film at the same time so it does not simply return.

On a planted tank the frustration is specific: the underwater scene looks pristine, but a reflective, oily film on top ruins the view and your photos. This guide explains why that film keeps coming back on a planted 150 litre tank, how to choose a skimmer for it, and how to protect floating plants and shrimp.

Why does a planted tank keep getting an oily film?

A surface film on a planted tank is usually a microbial biofilm feeding on organics at the surface, and it tends to gather where the water is still. The common causes are worth knowing, because a skimmer treats the symptom while these treat the cause:

• Feeding. Overfeeding leaves oils and proteins that rise to the top; feeding a little less makes a visible difference.
• Dead spots. Areas of low circulation let the film settle, which is why part of the surface can look worse than the rest.
• Filter maintenance. An overdue or undersized filter lets organics build up faster than they are processed.

Wiping it away with a paper towel, or raising the filter outlet, only helps for a day or two, and that is exactly why people look for a permanent fix. It is fair to worry that you might spend £75.90 and find the film comes back, so pair a skimmer with a small change to feeding or flow and you break the cycle for good.

What a 150 litre aquarium skimmer does day to day

A surface skimmer runs continuously, drawing the top millimetre or two of water through a comb and trapping the film in a sponge. Because the comb floats, it keeps skimming the actual surface rather than a fixed height, which matters on a display tank you photograph from above. For the underlying reason a clear surface helps the whole tank, see how gas exchange works in our aquarium protein skimmer guide.

Protecting floating plants, shrimp and fry

The most common question on a planted tank is whether a surface skimmer will suck up floating plants, and it is a reasonable one. The answer is that a floating comb spread over a wide intake, run on a gentle setting, skims the film without grabbing floating plants, fine leaf debris, shrimp or fry. The key is to start low: for the full method of dialling in the flow, see our adjustable aquarium skimmer guide.

Water level, evaporation and gurgling

Two practical points keep a skimmer quiet and effective. First, as the water evaporates the level drops, and if the comb cannot follow it the unit starts to suck air and gurgle; a floating comb on a 3-level bracket tracks the level, and a built-in air-intake silencer keeps the noise down. Second, topping the tank up regularly keeps the comb in its working range, so it never runs dry.

Choosing for a 150 litre tank

Match the skimmer to the tank. A unit rated for 100 to 150 litres sits at the top of its range on a 150 litre tank, which is what you want: enough surface movement to keep it clear, with the flow turned down to suit a planted layout. Check the stated tank range before buying, and for a smaller setup our 100 litre aquarium skimmer guide covers the basics.

The AquarSurfa Pro Clear for a 150 litre planted tank

For a planted or community tank at the top of the range, the AquarSurfa Pro Clear surface skimmer is sized for 100 to 150 litre aquariums. It uses a floating comb that self-adjusts to the water level on a 3-level height bracket, an adjustable flow dial so you can start gently, and a built-in air-intake silencer to cut gurgling. A corrosion-resistant stainless-steel shaft suits both fresh and salt water, heavy-duty suction cups hold it steady on the glass, and it comes with an internal sponge, needle cleaning brushes and a 1.5m cable. It is £75.90 inc. VAT (£63.25 ex. VAT), ships from UK stock with free next-day dispatch, and comes with a 12-month UK warranty and 30-day returns. It is rated 4.7 out of 5 from 341 reviews. Check the floating comb weekly and rinse the sponge every couple of weeks in old tank water; replacement sponges are available.

Frequently asked questions

Why does my planted tank keep getting an oily film on the surface?

It is usually a biofilm feeding on organics at the surface, driven by overfeeding, dead spots with low circulation, or an overdue filter. Wiping it or raising the outlet only helps briefly, so pair a surface skimmer with a small change to feeding or flow to stop it returning.

Will a surface skimmer suck up floating plants or shrimp?

Not if you run it gently. A floating comb spread over a wide intake, set on a low flow, skims the film without grabbing floating plants, fine debris, shrimp or fry. Start on the lowest setting and raise it only as needed.

What size aquarium skimmer do I need for a 150 litre tank?

Choose one rated to cover 150 litres; a unit designed for 100 to 150 litre tanks sits at the top of its range on a 150 litre aquarium. That gives enough surface movement to keep the film clear while letting you turn the flow down for a planted layout.

Why does my surface skimmer gurgle as the tank evaporates?

As the water level drops, a skimmer whose intake cannot follow it starts to draw air and gurgle. A floating comb on an adjustable bracket tracks the falling level, and topping the tank up regularly keeps the comb in its working range so it stays quiet.