• Cut to your glass, not to a stock size — Red Sea gives the formula outright: profile length = glass length minus 50 mm, profile width = glass width minus 50 mm.
• 8 mm thin strand, transparent netting — Red Sea's own specification. Fine enough to stop jumpers, open enough to feed and see through.
• Two mounting positions — the four hangers give inside-rim or on-rim mounting, so it suits rimless and rimmed open-top tanks.
• One cut-out included — the kit carries components for one customised cut-out to clear a filter, overflow or return.
• Spline roller supplied — the tool that presses the net into the profile channel is in the box, which is the part most DIY screen kits leave out.

Red Sea publishes a per-part-number contents list. For R42081 (90 x 60 cm / 36" x 24"):

Red Sea's product page and its assembly manual give different spline lengths for this kit, so we have not published a figure. There is enough supplied to complete one cover at the kit's maximum size.

• Cutting tools. The only tool in the box is the spline roller. You supply the saw, mitre box and measuring gear to cut the aluminium profiles.
• Additional cut-outs. The kit covers one cut-out. Red Sea's assembly manuals mark part R42085 as not included — that is the component set used for extra or zig-zag cut-outs around rim-mounted equipment.
• Extra hangers beyond the four supplied.
• The tank. This is the cover kit only.

Red Sea states that components are available separately to accommodate additional rim-mounted equipment such as lighting arms, auto-feeders and overflow boxes. We have not listed part numbers for those add-ons because Red Sea does not publish product names against them, and the numbers circulating on overseas retail sites are not confirmed by Red Sea. Ask us and we will confirm current part numbers with the distributor before you order.

Measure your glass, subtract 50 mm from each dimension, and check the result fits inside 90 x 60 cm. If it does, this is your kit. If the tank is larger, step up the range below.

From Red Sea's own aquarium selection chart, R42081 is the specified kit for:

• REEFER 250 and REEFER 250 DLX (fixed mount)
• REEFER 250 DLX (universal mount)
• MAX E-260

One honest caveat. Red Sea's assembly manual also shows R42081 as an option for the REEFER 170/DLX, REEFER XL 200/DLX and REEFER XL 300/DLX, while the selection chart assigns those tanks to the next kit up or down. The two Red Sea documents disagree. We have followed the selection chart above. If you own one of those three tanks, measure the glass and check against the kit's 90 x 60 cm maximum rather than trusting either document.

MAX, MAX E, MAX S and MAX Nano tanks are all covered somewhere in the range, but only the MAX E-260 maps to this 90 x 60 cm kit.

Red Sea is upfront that this is a do-it-yourself product. Their words: it offers versatility and customisability at a fraction of the cost of custom-built covers, but it does require proper DIY skills including planning, taking exact measurements and cutting aluminium profiles.

The sequence is measure, cut the profiles to the formula, join with the internal and external corners, lay the net over the frame, roll the spline into the channel to lock the net, trim the excess, then hang. Red Sea publishes video guides for the range on its support site.

Red Sea does not publish a tools list or an assembly time, so this page does not state one. Budget an unhurried afternoon for a first build.

Suitable for

• Open-top tanks where fish are jumping, or where you want to stop them before they do
• Rimless and rimmed tanks, using the two hanger positions
• Tanks needing a cut-out around a filter, overflow box or return
• Anyone who wants a made-to-measure cover without paying for custom fabrication

Not suitable for

• Supporting weight. Red Sea publishes no load rating for this cover. Do not rest lighting, lids or anything else on it. Where the frame needs to clear a light arm, it is cut around it, not loaded by it.
• Anyone unwilling to cut aluminium. Nothing in this kit is pre-cut to a finished size.
• Tanks whose glass, minus 50 mm per side, exceeds 90 x 60 cm.
• Covered or hooded tanks that already seal at the top.

• Red Sea Filter Media Bags — the other genuine Red Sea consumable most Reefer and MAX owners keep spare.
• Red Sea Coral Pro Salt — a cover cuts evaporation, which steadies salinity between top-ups.
• Red Sea Marine Care Multi Test Kit — for the routine checks on a newly set up REEFER or MAX.
• Red Sea KH/Alkalinity Pro Test Kit — less evaporation means less alkalinity swing to chase.

Red Sea warrants its aquarium products against manufacturing defects in material and workmanship for 24 months from date of purchase, excluding normal wear and tear and consumable items. Red Sea does not name the net cover in its warranty text, so treat 24 months as the product-class term rather than a guarantee specific to this kit. Any manufacturer warranty is in addition to your rights under the Australian Consumer Law and does not limit them.

The kit ships as a long flat carton because of the profile lengths, so it will not fit a standard satchel.

What exactly comes in the Red Sea DIY Net Cover kit?

For R42081 (90 x 60 cm): six external corners, two internal corners, four hangers, one front spacer, two 88 cm profiles, three 57 cm side and space profiles, two 10 cm cut-out profiles, spline, 3 m of net, and one spline roller. Cutting tools are not included — the spline roller is the only tool in the box.

How do I work out where to cut the profiles?

Red Sea's formula is glass length minus 50 mm for the profile length, and glass width minus 50 mm for the profile width. Measure the glass itself, not the outside of the cabinet or the rim.

Will the Red Sea 90 x 60 cm net cover fit my REEFER?

Red Sea's selection chart specifies R42081 for the REEFER 250, REEFER 250 DLX in both fixed and universal mount, and the MAX E-260. For any other tank, measure the glass and check that each dimension minus 50 mm falls within 90 x 60 cm.

Can I cut a hole for my overflow or filter?

Yes. The kit includes components for one customised cut-out, using the two 10 cm cut-out profiles. For additional cut-outs or to work around lighting arms and auto-feeders, Red Sea sells separate components — part R42085 is marked as not included in Red Sea's assembly manuals.

Can I rest my light on the net cover?

No. Red Sea publishes no weight or load rating for the cover, and it is a tensioned mesh in an aluminium frame, not a shelf. Mount lighting on its own arm or bracket and cut the frame around it.

Does it fit a rimless tank?

Yes. The four hangers give both inside-rim and on-rim mounting options, and Red Sea describes the range as suitable for most open-top aquariums. Red Sea does not publish a maximum glass thickness for the hangers, so if your glass is unusually thick, check with us before ordering.