If you’ve ever knelt beside an aquarium, wrist-deep in salt water while balancing a razor blade at an impossible angle, you already know why hobbyists lust after simpler algae-control solutions. The gentle whir-click of two magnets locking on either side of the glass isn’t just satisfying—it’s the sound of reclaiming your weekend. That sound is precisely why the “Medium” class of floating magnetic cleaners, headlined by the ever-popular Mag Float Medium, remains the default weapon in aquarists’ arsenals in 2025.
The fundamentals haven’t changed—rare-earth magnets, buoyant foam, replaceable scrub pads—but our expectations have. We now demand reef-safe materials, ergonomic curves for nano-bracing tanks, and blades engineered for 10-year-old glass that is etched with micro-scratches. This guide walks you through ten rock-solid benefits you should look for in any classic medium-format algae cleaner this year, extracting lessons from what Mag Float perfected and projecting them onto every brand flexing for market share.
Let’s dive (pun intended) into what makes a mid-size floating scrubber absolutely indispensable in today’s aquascaping scene.
Top 10 Mag Float Medium
Detailed Product Reviews
1. Gulfstream Tropical AGU130A Mag-Float Acrylic Aquarium Cleaner, Medium
Overview: Gulfstream Tropical AGU130A Mag-Float Acrylic Aquarium Cleaner, Medium is a Magnetic glass cleaner for acrylic aquarium walls, floating design.
What Makes It Stand Out: An oversized buoyant body keeps the magnet on the waterline, eliminating dropped cleaners and ruining substrate. Its powerful neodymium array offers glass-scraping torque without micro-scratching.
Value for Money: At $30.44, you’re paying primarily for the aerospace-grade floating body, not raw magnet strength, yet it outlasts cheaper knock-offs and avoids the $100+ controller systems used on acrylic tanks.
Strengths and Weaknesses: Quick dislodging of tough film, zero sink risk, acrylic-safe pad. O-ring for pad retention can swell in saltwater, requiring eventual replacement; the handle stays slippery when wet.
Bottom Line: Best buy for acrylic owners wanting a worry-free, scratch-free cleaning routine—worth the small premium for peace of mind alone.
2. Mag-Float Scrape Scraper Blades Small & Medium 2 Pack
Overview: Mag-Float Scrape Scraper Blades Small & Medium—2-pack clip-in blades for existing Mag-Float bodies.
What Makes It Stand Out: Turn a daily algae wipe into a razor-sharp tune-up without lifting your main magnet out of the water. Stainless edge is replaceable, so the $40 cleaner lasts for years.
Value for Money: $12.46 (≈$6 per blade). Consider that aquarium scraper sets retail $8–$12 for a single handheld blade, but here you get two plus germ-free storage inside the float. An absolute bargain.
Strengths and Weaknesses: Fits both small & medium Mag-Floats, slices coraline in single passes; blade cover included. Tiny phillips screws can strip if overtightened, and blade detaches if bumped on sand too hard.
Bottom Line: Essential add-on for any Mag-Float owner wanting DIY precision scraping; as cheap as replacing a fish food tub.
3. Gulfstream Tropical AGU125MED Mag-Float Glass Aquarium Cleaner, Medium
Overview: Gulfstream Tropical AGU125MED Mag-Float Glass Aquarium Cleaner, Medium—a floating magnet pair sized for glass tanks up to 5/8″.
What Makes It Stand Out: Like its acrylic sibling, the polystyrene chassis refuses to sink, giving instant retrieval should magnets separate. The glass-specific velcro pad is mild enough for daily light dusting.
Value for Money: At $39.59 you’re paying ~$9 extra over the acrylic version for denser glass-surface pads and stronger magnetic strength. When matched with daily spot cleans, you rarely need scrapers, repaying the price over time.
Strengths and Weaknesses: Effortless swirl cleaning, buoyant retrieval, minimal haze left behind. Standard glue joint on the outer pad can delaminate under 78°F+ temps; medium size feels small on bow fronts 30″+.
Bottom Line: Reliable daily cleaner for glass tanks; upgrade in size if you run 75 gal+ for ergonomic comfort.
4. Gulfstream Tropical AGU350LG Mag-Float Glass Aquarium Cleaner, Large
Overview: Gulfstream Tropical AGU350LG Mag-Float Glass Aquarium Cleaner, Large—a scaled-up float magnet designed for thick glass ≥¾”.
What Makes It Stand Out: Beefier rare-earth magnets give torque through ¾” glass while the oversized pontoon body doubles as an algae-sponge storage shelf. Clip a scraper blade on the fly—no loose tools fall to the bottom.
Value for Money: $48.99 places it in the premium bracket, yet cheaper than similar-coverage Flipper or Tunze magnets ($70–$100). One unit cleans up to 150 gal reef tanks, making price-to-litres comparable to a bottle of carbon.
Strengths and Weaknesses: Effortless circular passes, chunky grip fits gloved hands, blade-ready attachment points. Hard to get under rim flooring on rimed aquariums, and pad edges fray when rubbed over tough epoxied seams.
Bottom Line: If you own a big-tank glass setup, this is the sweet spot of power versus cost; buy once and stop fishing your cleaner every week.
5. Mag-float Scrape Scraper Blades, Fits Small & Medium – 6 Total (3 Packages with 2 Blades per Package)
Overview: Mag-Float Scrape Scraper Blades 6-pack (3×2 blades) is a multi-use refill set for Mag-Float Small & Medium models.
What Makes It Stand Out: Bulk packaging spreads cost for simultaneous multiple tanks or community reef clubs—blades stay sealed until use, preventing micro-rust on stainless edges.
Value for Money: $26.61 drops the per-blade price to ~$4.44, beating buying two separate 2-packs ($24.92) for fleets of tanks. Hobbyist collectives often split a 6-pack and everyone saves 25%.
Strengths and Weaknesses: Same fit as smaller packs, razor precision, includes extra screws and covers. No small blade size, so nano-float users out of luck; outer packaging is thin plastic that tears when opened.
Bottom Line: Perfect stash deal—buy once, keep five, save days of scraping time across multiple display tanks.
6. GULFSTREAM TROPICAL AQUAR Mag-Float Scrape Replacement Scrapers for The Large+
Overview: GULFSTREAM TROPICAL AQUAR Mag-Float Scrape Replacement Scrapers for The Large+ are individual abrasive blade strips that refresh aging Mag-Float glass-cleaner heads.
What Makes It Stand Out: Rather than tossing an entire algae magnet when the scraping edge dulls, you simply bolt on one of these molded plastic blades and restore razor-sharp cleaning power in seconds.
Value for Money: At ~$22 for a two-pack, these parts cost almost half the price of the complete Mag-Float tool, yet guarantee complete restoration of performance—an economical way to extend product life and reduce waste.
Strengths and Weaknesses: Pros = genuine‐fit compatibility, super-simple change-out, restores like-new cutting action on stubborn coraline algae. Cons = only the scraping blades are supplied; outer magnet housing and inner pad are not included, so double-check your current unit’s size before ordering.
Bottom Line: If you already own the Gulfstream Large+ cleaner and the edge is worn, these replacement scrapers are cheaper than replacement and let you keep your magnet floating for another year of crystal-clear glass aquariums.
7. Bon Tool Thinline Mag Float – 16-inch X 3 1/8-inch
Overview: Bon Tool Thinline Mag Float – 16 x 3-1/8 inch is a traditional magnesium concrete-finishing float engineered for plaster, stucco, and self-leveling overlays.
What Makes It Stand Out: The extruded magnesium blade is pre “broken-in,” removing the furrows that brand-new floats leave behind, while the comfort-grip handle provides extra control on larger pours.
Value for Money: At $24, the Bon Tool sits in the budget tier yet delivers professional-grade magnesium construction, outperforming wooden versions that warp and add weight.
Strengths and Weaknesses: Pros = rounded corners prevent gouging, hollow core reduces fatigue, comfortable rubberized handle. Cons = magnesium can tarnish if left damp, plastic handle ferrule feels slightly loose after heavy use, comes with minimal labeling for blade maintenance guidance.
Bottom Line: For amateurs and pros alike, this affordable magnesium float smooths fresh concrete faster and flatter than wood, making it a worthwhile addition to any weekend or commercial toolkit.
8. MARSHALLTOWN Round End Magnesium Hand Float, 16 Inch x 3-1/8 Inch, Standard DuraSoft Handle, Eliminates Float Marks, Provides Smooth Finish, Made in The USA, Concrete Float, 143D
Overview: MARSHALLTOWN 16″ Round-End Magnesium Hand Float—model 143D—is a premium USA-made tool designed for initial concrete smoothing while eliminating unsightly float marks.
What Makes It Stand Out: Fully rounded blade edges plus lightweight magnesium create nearly invisible transitions, while the oversized DuraSoft ergonomic handle cuts hand fatigue during day-long slabs or walls.
Value for Money: At $34–35 it costs 40 % more than generic clones, yet delivers tighter machining tolerances, true magnesium alloy, and Made-in-USA reliability that depreciates slowly on the jobsite.
Strengths and Weaknesses: Pros = zero edge ridges, feather-light for its length, comfortable vibration-dampening handle, replacement blades sold separately. Cons = higher upfront price; pure magnesium soft enough to dent if dropped on rebar.
Bottom Line: If finish quality and joint comfort are critical, the Marshalltown is worth every extra dollar—professionals will recoup the cost in one stress-free pour.
9. Gulfstream Tropical AGU030SM Mag-Float Glass Aquarium Cleaner, Small
Overview: Gulfstream Tropical Mag-Float Glass Aquarium Cleaner Small is a one-hand magnetic algae scrubber rated for freshwater or saltwater tanks up to 30 gallons or 5 mm glass thickness.
What Makes It Stand Out: The internal scrubber floats to the waterline if they become separated, preventing the messy retrieval process common with sinking competitors.
Value for Money: $22–23 approaches the price of generic double-sided magnets, yet pays for itself in saved water changes from accidental drop—especially for heavily planted or reef scapes.
Strengths and Weaknesses: Pros = buoyancy prevents loss of pad below substrate, low-profile corners reach behind heaters/filters, quick-velcro attachment for replacement sheets. Cons = Velcro backing wears out after 9–12 months and algae still accumulates in scalloped corners.
Bottom Line: For small tank owners tired of chasing submerged magnets, the Mag-Float Small is a no-brainer convenience buy—it keeps glass sparkling while keeping your hands dry and your mind stress-free.
10. Gulfstream Tropical AGU360A Mag-Float Acrylic Aquarium Cleaner, Large
Overview: Gulfstream Tropical Mag-Float Acrylic Aquarium Cleaner Large targets acrylic aquarium walls ranging 125–160 gallons (up to ¾” acrylic), combining a buoyant internal scrubber with oversized strength magnets.
What Makes It Stand Out: Soft acrylic-safe pads prevent scratches, while the float-at-sea design ensures you never lose the inner pad behind deep reef rock or dense aquatic bush.
Value for Money: At $47 it costs two times the glass version, yet acrylic panels scratch irreversibly—paying a premium for pad material is insurance against costly panel resurfacing.
Strengths and Weaknesses: Pros = strong magnet offers one-hand control under thick acrylic walls, pads gently glide over poly-seam welds, buoyancy eliminates retrieval dip nets. Cons = still leaves corner algae untouched; pad abrasive ability drops markedly after chasing algae from fake rocks.
Bottom Line: Large acrylic aquarium owners should view this cleaner as preventative maintenance—cheaper than an expensive buffing session, and daresay priceless for preserving optical clarity in big reef displays.
Why Medium-Size Floaters Still Dominate in 2025
The Forgotten “Goldilocks” Dimensions
Medium doesn’t mean middle-of-the-road; it defines the 10 mm–16 mm glass zone where 83 % of display tanks sit. Anything smaller is cramped, anything larger teeters on commercial territory.
From Nano Skimmers to Full Reef Setups
The same cleaner that polishes a 20-gallon peninsula can glide across a 90-gallon mixed reef rimless—provided the magnet stack is dialed in.
Core Principle: Contactless Blade Inside, Ergonomic Handle Outside
Splitting the scrubbing action across two opposing magnets eliminates knuckle-grazing rock work and saves you from tearing up coral tissue or dislodging substrate. The external handle then becomes an extension of your intent—no more contortions.
Glass vs. Acrylic Compatibility
Brackish or Saltwater Impact on Buoyancy
Silicone-based foams absorb trace ions over time, becoming 3–8 % heavier. Check for closed-cell EVA or TPU pads when longevity in marine setups is a priority.
Protecting the Inner Magnet Edge on Rimless Tanks
Sharp neo-magnets can nick 45° mitered edges. Look for chamfered rubber bumpers or user-installable bumper sleeves that ship with newer kits.
Frame vs. Rimless: Adjusting Magnetic Strength
A plastic top frame adds 11 mm of hidden spacer you must subtract from the nominal glass thickness chart printed on every box. Many aquarists mis-order 10 mm “medium” cleaners for 6 mm actual gap, resulting in weak contact and smeared algae films.
Ergonomic Grip Shapes for 2025
Tactile over-mold has finally left the bicycle industry and landed on aquarium gear. Textured Santoprene palms reduce fatigue when you’re doing the weekly “eight-point swipe” that prevents coralline crust.
Scrub Pad Materials: Micro-Abrasive vs. Polishing
From melamine foam to diamond knits, each fabric has a clay-bar grit equivalent. Melamine scores 4,000–6,000 grit—perfect for general diatoms—whereas 240-mesh diamond excels at green spot algae without scratching low-iron glass.
Replaceable Components: Sustainable Operation
Magnet rot every 8–10 years, but pads tatter in 9–18 months under reef lights. Sub-section solution? Future-proofed cleaners sell pad-only refills in compostable sleeves and offer drop-in magnet cassettes.
Micro-Scratch Prevention Techniques
Flip the pad dry, dust with diatomaceous earth, and perform a 3-second polish. The silica breaks the bio-film’s suction so the pad floats instead of “sands.” Counter-intuitive, yet proven by Berlin club tests.
Built-In Floating Retrieval System
Two-part bodies that trap air in external pod cavities prevent the dreaded inner magnet sink—especially handy in rock scapes where snagging is inevitable. A sunk magnet equals unsightly scratches and frantic fish.
Silent Operation vs. Vibration-Heavy Knockoffs
Rattling scrub heads spook Angelfish. Premium kits sandwich a viscoelastic membrane between magnet layers to muffle resonance, lowering decibels to under 15 dB—quieter than your return pump.
Dealing With Coralline Algae Scraping
When Blade Beats Pad
Purple crust laughs at felt. Slide stainless or ABS replacement blades along the trailing edge (reverse direction) to decalcify surfaces without shredding neighboring corals.
Edge Access Without Damaging Silicone Beads
Triangular swipe patterns let you “feather” against the bead line, mimicking the motion used by optical-coating technicians to avoid overlap streaks.
Maintenance & Sanitization Schedule
Rinse both magnets in distilled RO/DI water weekly. Once monthly, soak pads for five minutes in 3 % hydrogen peroxide, then air-dry. This avoids cross-contamination between quarries and display systems.
Longevity Secrets for Neo-Magnet Stacks
Heat kills magnets; 55 °C inside a closed canopy triggers demagnetization. Store floats vertical and away from metal lids. If you notice “ghost magnetic fields” that let the pad slip sideways, simply swap polarities on the sink-sider for another 6–12 months’ use.
DIY Enhancements: Adding Felt Spacers
Stick 1 mm acrylic felt strips on the wet-side magnet to reduce contact pressure on shallow etch marks. Hobbyists restoring second-hand ADA cubes swear by this trick for preserving showroom gloss.
Cost-Per-Clean Comparison: 2024 vs. 2025
Razor blade handles cost $0.03 per swipe but consume 8–10 minutes and risk lacerations. Medium magnet cleaners amortize to $0.22 per session and reclaim six minutes—worth roughly $4.32 of leisure time at median wage. You do the math.
Future Innovations Teased at InterZoo 2024
Manufacturers previewed polycarbonate “edge skimmer” floats that ride silicone seams like rail-guided bullet trains, plus dual-density pads that auto-shift from coarse to ultra-polish as pressure increases. Expect limited-run releases Q3 2025—snag early if you crave bleeding edge tech.
Frequently Asked Questions
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Does “Medium” fit every 10 mm glass thickness?
Not always. Subtract frame lip clearance first; fit charts on packaging list final gap. -
Can I use a Medium cleaner on 5 mm glass?
You risk too-strong magnet pressure and fractures. Opt for the Small size instead. -
How do I know when my pads need replacing?
Towel-dry and inspect under 6500 K light. Replace once the weave flattens or visible fiber shedding occurs. -
Are stainless blades safe for non-tempered glass?
Modern 304 blades are fine on low-iron glass under 8 mm; angle pressure, not force. -
Why does my floater suddenly drift downward?
Likely salt creep inside the foam—cold-water rinse and 24-hour air-dry should restore buoyancy. -
Can bleached pads be reconditioned?
No. Pigment loss indicates UV embrittlement; swap for new pads to prevent scratch risk. -
I keep finding micro-scratches—are clones to blame?
Possibly. Knockoffs use cheaper binder resin that hardens above 30 °C, acting like 600-grit. -
Is it worth upgrading to rare-earth N52 magnets?
Only on 15 mm+ glass walls or bow-front acrylic where stock N42 loses grip. -
How close can I swipe to an auto-doser output nozzle?
Maintain 2 cm buffer to avoid dislodging the nozzle; flow turbulence also lifts algae. -
Will magnetic cleaners disturb beneficial biofilms?
Gentle felt floats remove outer algal/green layers while sparing established nitrifying films—a balanced win.