Oase Biomaster Canister Filter — Full Setup, Unboxing & Maintenance Guide

The Oase Biomaster series is one of the best canister filters on the market — and one of the most misunderstood when it comes to setup. In this video, Henry from Nature Aquariums does a full unboxing and setup walkthrough of the Biomaster canister filter, covers the optional accessories (shut-off valves, Thermo heater, and Cleartron UV clarifier), shares pro tips for installation, and walks through a complete cleaning and maintenance routine. If you own a Biomaster or are thinking about getting one, this is the video to watch.

Biomaster Thermo vs. Regular — What's the Difference?

Every Biomaster canister filter comes in two versions:

Regular — filter only; includes an adapter ring so you can add an Oase inline heater later
Thermo — comes with the heater pre-installed inside the filter head; temperature control is always visible and accessible

If you buy the regular version and decide to add a heater later, check the chart on the side of the box — Oase specifies the correct heater size for each model. You cannot use a heater that's longer than the filter was designed for.

What's in the Box

Every Biomaster filter includes:

5/8" (16/22mm) tubing
Heater adapter ring
Rainbar / spray bar and intake
Suction cups
Directional outflow nozzle
Blue compression nuts, inflow/outflow fittings, and connectors
Full color instructions

Pro Tip: Soften Your Tubing Before Installing

This is one of Henry's best tricks and it makes a huge difference. Before installing, coil your tubing and submerge it in a large pot of water heated to about 190°F — just before boiling. Pull it out and the tubing will be completely limp and flexible, like wet spaghetti. This does two things:

Eliminates the coil memory so the tubing runs cleanly without kinking
Softens the ends so they slide easily over barbed fittings — as the tubing cools and shrinks, it creates a tight airtight seal

Always wear gloves — the tubing will be very hot. Work quickly; you have a limited window before it stiffens back up. Leave 8–10 inches of slack so you can rock the filter during the "burping" process after startup.

Understanding the Blue Compression Nuts

This trips up a lot of people. The blue nuts on the fittings work counterintuitively — you tighten the connection by loosening the nut. Slide your tubing onto the fitting, then back the blue nut off until it clamps down tightly against the vinyl tubing. Once you know this, the whole system makes a lot more sense.

Optional Accessories Worth Having

Shut-off valves — Oase makes these specifically for their filter lineup. They let you disconnect your tubing from the tank without draining anything, which makes filter maintenance much cleaner and faster.

Cleartron UV clarifier — plumbs inline with any Biomaster (or Filtosmart) filter. Designed to improve water clarity by eliminating free-floating algae and pathogens. Henry runs one on the store's 130-gallon discus planted tank and the results speak for themselves.

Setting Up the Filter

Assemble your spray bar or outflow nozzle and hang it on the tank
Run your hot, softened tubing from the tank down to the filter — inflow and outflow fittings are identical and interchangeable, but are labeled In and Out. The swivel connectors let you orient them in any direction.
Before plugging in, push the primer button on top of the filter. You'll feel strong suction as it draws water in and fills the canister. Keep priming until you no longer hear water rushing in and no more air bubbles are coming from the outflow.
Once full, plug in the filter. Gently rock it side to side and front to back to "burp" any trapped air.
If you have the Thermo version, plug in the heater only after the filter is running and full of water.

Media Order — Why Biological Media Goes at the Bottom

A common question is why biological media sits at the bottom of the Biomaster. Here's why: water enters through the pre-filter sponge on the outside of the canister, then flows upward through the trays from bottom to top. The bottom tray hits the water first — which is exactly where your biological media (Oase Helix, Matrix, Sera Siporax) should be. The polishing sponge at the top handles final filtration and breaks up any remaining air bubbles before water exits.

Weekly & Monthly Maintenance

Weekly — pre-filter cleaning (under 3 minutes):

Shut off power to the filter
Close the water supply lever
Place a rag on top of the pre-filter before removing — it will drip
Pull the pre-filter, rinse in dechlorinated tap water, add a drop of dechlorinator, reinstall
Open the supply lever — it will begin refilling automatically. Once full, restore power.

Every 3–6 weeks — full canister cleaning:

Unplug the filter and heater
Slide the disconnect lever to the unlock position — this shuts off water flow
Use the handle to carry the canister to a sink
Open the head using the blue latches (raise the handle first — this is a safety interlock)
Remove trays one at a time; rinse media in dechlorinated water
Replace chemical media (Purigen, polishing pads) as needed
Remove the impeller by rotating and pulling — clean the stainless steel shaft and housing
Reassemble in reverse order; align the heater port with the heater cap before latching
Reinstall, reconnect tubing, open supply lever, prime if needed, then restore power to filter first — heater second

Video Chapters

0:00 — Introduction & overview of the Biomaster series
1:00 — Thermo vs. regular: what's in the box
2:00 — Accessories: shut-off valves and Cleartron UV clarifier
3:00 — Unboxing: tubing, fittings, spray bar, and hardware explained
4:30 — Blue compression nuts: how they actually work
5:30 — Pro tip: softening tubing in hot water for easy install
7:00 — Setting up tubing runs and leaving slack for burping
8:00 — Heater port: regular cap vs. Thermo install
9:30 — Filter controls: disconnect lever, pre-filter removal, primer button
11:00 — Inside the filter: media trays, Helix media, sponges explained
13:00 — Why biological media goes at the bottom
14:00 — Impeller removal and pump head maintenance
16:00 — Live demo: 130-gallon discus planted tank running dual Biomasters
17:30 — Weekly pre-filter cleaning walkthrough
20:00 — Full canister deep clean walkthrough
25:00 — Reassembly, repriming, and restart
27:00 — Final thoughts and wrap-up

Bottom Line

The Oase Biomaster is one of the best-engineered canister filters available. The pre-filter system alone sets it apart — weekly maintenance takes under three minutes and keeps the main canister clean for weeks at a time. The Thermo version simplifies heating, the shut-off valves make maintenance clean and stress-free, and the build quality is exceptional. Henry and the Nature Aquariums team have been running these for nearly two years across multiple store tanks with outstanding results.

We carry the full Oase Biomaster lineup — including the Thermo versions, shut-off valves, and Cleartron UV clarifier — at natureaquariums.com. Shipped right to your door.