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The right aquarium substrate depends on one question: are you growing plants or keeping fish over decoration? For a serious planted tank, aquasoil earns its premium — it feeds roots and softens water in ways gravel never will. For a fish-first community tank, plain gravel remains the easiest bed to keep clean, and sand is the specialist’s choice for bottom-dwellers like corydoras and loaches. Everything else is detail — but the details decide whether you’re rebuying substrate in two years.

Match the bed to the tank, not the trend

Keeping fish with plastic or hardy plants? Gravel.

Gravel’s virtue is maintenance. Debris sits on top of or between the stones where a gravel vacuum lifts it easily, water flows through the bed instead of compacting it, and it never clouds the water column. It’s also honest about what it isn’t: despite what some packaging implies, inert substrates carry little plant nutrition — as planted-tank resource The 2Hr Aquarist puts it, most “do not naturally contain significant amounts of nutrients for plant growth, despite what the marketing says.” Anubias, java fern, and other plants that feed from the water column do fine; root feeders will want help.

Keeping corydoras, loaches, or a natural riverbed look? Sand.

Fine sand — CaribSea’s Super Naturals line runs roughly 0.5 to 1 mm grain per the product listing — lets barbeled fish sift and forage the way they would in a river, which is the main reason keepers of corydoras and kuhli loaches choose it. Waste stays visible on the surface rather than sinking in, which looks messier but siphons faster. The trade-offs: sand can compact over time, it wanders into filter impellers if stirred carelessly, and like gravel it’s nutritionally inert.

Growing a carpet, stems, or a shrimp colony? Aquasoil.

Aquasoil is the only option here that actively changes your water and feeds your plants. Commercial aquasoils come “enriched with ammonia and other nutrients, which is great for plant growth,” per The 2Hr Aquarist’s substrate guide, and most contain peat that buffers pH to just below neutral — the soft, slightly acidic conditions most aquatic plants and dwarf shrimp prefer. Fluval markets its Stratum, collected from the foothills of Japan’s Mount Aso volcano, as supporting exactly that neutral-to-slightly-acidic range while its porous granules give beneficial bacteria and newborn shrimp somewhere to hide. The same guide’s bottom line on growth is blunt: most plants simply grow better in soil.

The catch is a lifespan clock. The nutrient charge diminishes and eventually “need[s] to be replenished in the form of root tabs,” per the same guide — though the structural benefits of the porous granules persist for years. That ammonia charge also means cycling an aquasoil tank before adding livestock is non-negotiable.

What a two-inch bed really costs: our 20-gallon math

We priced a two-inch bed for a standard 20-gallon-long (30 × 12-inch footprint) using the hobby’s common planning rule of about one pound of sand or gravel per gallon per inch of depth, and current retailer listings as of July 2026. Aquasoil granules are much lighter per unit of volume, so weight rules don’t transfer; we used the two-bag load owners most commonly report for this footprint, and you should treat that line as an estimate.

The surprise in that table: aquasoil isn’t the expensive option upfront — it lands within a few dollars of plain sand and under the “planted” gravel. What you’re really paying for aquasoil is the maintenance clock, not the checkout price. Eco-Complete’s premium buys its dark basaltic look and CaribSea’s claim of packaged live bacteria, but experienced owners widely note it behaves as an inert gravel that still needs root tabs for hungry plants.

Dealbreakers before you pour

• Stocking fish the same week? Skip aquasoil — its ammonia release demands a full cycle first.
• Keeping hard-water fish like African cichlids or livebearers? Aquasoil’s acid-leaning buffer works against them; use inert sand or gravel.
• Hate cloudy water? Rinse sand and gravel thoroughly; with aquasoil, fill slowly over a plate and never rinse it.
• Strong filter intake near the bed? Fine sand plus an unguarded impeller is how filters die — use a pre-filter sponge.

How we compared

We drew on planted-tank guidance from The 2Hr Aquarist, manufacturer claims from Fluval and CaribSea product pages, current Petco and PetSmart listings for pricing, and aggregated long-term owner reports on compaction, depletion, and rescapes. We don’t run test tanks, and our editorial standards explain how we verify what we publish. Prices are approximate, current as of publication, and change frequently — confirm the latest price with the retailer before buying.

Fishkeepers also ask

Can I grow plants in plain gravel?

Yes, within limits. Water-column feeders like anubias and java fern don’t care what’s below them, and root feeders can manage in gravel with regular root tabs — you’re just supplying the nutrition the substrate doesn’t have.

How deep should an aquarium substrate bed be?

Around two inches is the common target for planted setups — enough for roots to anchor and spread — while fish-only tanks often run shallower beds of an inch or so, which trap less debris.

Do I have to replace aquasoil when its nutrients run out?

No. The porous structure keeps benefiting roots and bacteria for years, per The 2Hr Aquarist — most keepers just push root tabs into the depleted bed instead of tearing the tank down.

Can I cap aquasoil with sand or gravel?

Keepers do it for looks and to keep soil granules from floating, but the layers mix over time as fish dig and plants are uprooted. If you go this route, use a thin cap and expect it to be temporary.

Building out the rest of the tank? Our starter aquarium size comparison helps you pick the box itself, the filter face-off covers what keeps the water clean above your new bed, and the heater comparison rounds out the hardware. More in Fish & Aquariums.

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For a planted tank light, disclosure starts with Chihiros Aquatic Studio: the WRGB II Pro 120 costs $579.00 and publishes no wattage, no lumens, no PAR and no PPFD figure for it. Neither does the Pro 30 at $229.00. Fluval’s current Plant 4.0 LED, the fixture that replaced the spec-sheet-heavy Plant 3.0, publishes none of those either — and the delisted Plant 3.0 pages still sitting on Fluval’s own site publish all of them. Of the four brands here, the only one that prints a PAR number at all is hygger, and it prints one number with no distance attached. NiCrew’s ClassicLED Plus publishes 1150 lm, 22 W and a 117-LED colour breakdown.

I’ve spent enough time around planted freshwater tanks to know a spec sheet beats a marketing photo every time. When a maker will not print a wattage or a PAR number, that omission is telling on its own. So this comparison scores what each brand discloses before it scores how the fixture looks over the tank.

Published July 17, 2026 · Last updated August 31, 2026 · By Nate Colburn · Our editorial standards

How We Scored These Four Planted Tank Lights

A planted tank light has one job: put photons on leaves. You cannot check whether a fixture does that job unless the maker tells you how much light it makes and where that was measured. So the heaviest axis here is disclosure, at 35%, and it is not a proxy for quality — it is the only axis on which any of these four can be checked at all.

Availability carries 20% because two of the four fixtures this comparison was built on are gone. Price gets 15% because two of the four will not show one. Warranty gets 15% because one of the four will not tell you its length until after you own the light. Spectrum gets the last 15% because a planted light sold on colour rendering ought to say which wavelengths it renders.

Fluval finishes last, and the reason is not that the light got worse. The reason is that Fluval replaced a product line that published a full spec block with one that publishes marketing copy.

To Read Fluval’s Old PAR Table, Subtract Three Quarters by 12 Inches

The Plant 3.0 product pages are still live on fluvalaquatics.com even though the fixture is off the lighting menu, and they carry the best disclosure any of these brands has ever offered: lumens, LED count by colour temperature and wavelength, and a PAR/LUX table at three stated depths. Here is that table, as Fluval prints it, with the drop computed.

Two things fall out of Fluval’s own numbers. The first: the headline figure is a 3-inch figure. Your carpet plants are not three inches from the fixture. On a standard 20-gallon tank the substrate sits roughly 12 to 16 inches down, and at 12 inches the 22W model is delivering 80 against its headline 442 — 18.1% of it.

How Much Light Reaches the Substrate at 12 Inches?

At 12 inches, a 59W fixture reads only 136 PAR against a 22W fixture’s 227 at 6 inches. That gap means the smaller light, positioned closer, beats the bigger light on a deep tank by 1.67 times. Going from 22W to 59W — 2.68 times the wattage — buys you only 1.7 times the PAR at the same 12-inch depth, because most of what the bigger fixture adds is length, not depth.

Fluval does not state whether those readings were taken in air or through water, at the centre of the tank or off to a corner, or at what dimming level. So the decay above is real and Fluval’s own, but its absolute values are not transferable to your tank. Fluval does not claim otherwise; the conditions simply are not printed.

To Compare Two PAR Numbers, You Need Three Things hygger Omits

hygger’s planted aquarium lighting page carries exactly one sentence of light-output data: “White daylight blends RGB LEDs for high PAR value, from 201(20W model) to 420.1(72W model).” No distance is given, and there is no statement of air or water. It gives no position in the tank, and no brightness setting is named, on a fixture the same page sells with ten brightness levels.

Set that beside Fluval’s 442 at 3 inches and you can see the problem. 420.1 and 442 look like the same kind of number. One is anchored to a stated distance and the other is anchored to nothing. Dividing either by a price produces a ranking with no basis under it, which is why no such ranking runs on this page.

hygger does better than everyone else on the part it does publish. It names its wavelengths: red at 620–625 nm, blue at 450–455 nm, green at 520–525 nm, alongside 6500K white. Chihiros describes the WRGB II Pro as “4 in 1 WRGB leds” and gives no nanometres at all.

How Should Grow Lights Report PPF by Wavelength?

Plant lighting outside the aquarium hobby is not this vague, and the contrast is instructive. The DesignLights Consortium’s Horticultural Technical Requirements V4.0, effective October 2025, requires a listed fixture to report “Photosynthetic Photon Flux (Φp or PPF), (µmol × s-1)” tested to ANSI/IES LM-79, across the 400–700 nm range, “with 400-500 nm, 500-600 nm, and 600-700 nm bins reported alongside the total.” Far-red flux from 700 to 800 nm gets reported separately. The document takes its definitions from ANSI/ASABE S640, the standard that defines PAR, PPF and PPFD for plants.

None of these four aquarium fixtures claims LM-79 testing, a DLC listing, or S640 nomenclature. That is not an accusation — DLC listing is a commercial-horticulture programme and nobody is obliged to join it. It is a measuring stick. A greenhouse grower gets photon flux in three wavelength bins under a named test method. An aquarist gets “high PAR value” and a price.

Is There a Published PPFD Target for Planted Tanks?

No university, government or peer-reviewed source publishes a PPFD target for planted freshwater aquariums, at least none I could find. The familiar low/medium/high bands of roughly 20–40, 40–80 and 80-plus µmol/m²/s at the substrate come from hobby sites, and I could not trace them to any primary source. They appear here only as what they are: hobby convention, with no primary source I could trace behind it.

What is not in doubt is the direction. NOAA’s National Ocean Service states that sunlight “may travel about 1,000 meters (3,280 feet) into the ocean under the right conditions, but there is rarely any significant light beyond 200 meters,” and that within that upper layer “the intensity of light rapidly dissipates as depth increases.” That is open ocean, not a 20-gallon tank, and I am not going to pretend the magnitudes transfer. Water attenuates light. How much yours attenuates depends on your water, and no maker here measures through it.

How Long Is the Warranty on Each Planted Tank Light?

Fluval’s own extended-warranty page states that a product “is guaranteed for defective parts and workmanship as of the date of purchase for the period of time indicated within the instruction manual and/or warranty card.” It names no duration. The manual and the warranty card arrive in the box.

The other three are findable before you pay. NiCrew publishes “one (1) year from the date of the original purchase” plus a 30-day money-back window. Chihiros publishes a one-year limited warranty from the date of receipt. hygger publishes the longest: “Extended Warranty: 2 Years (ELEC) / 3 Years (NON-ELEC).”

To Buy a Plant 3.0 or a WRGB II Today, Read the Collection Page First

Both of the fixtures this comparison was originally built around have left their makers’ catalogues, and they left in two different ways.

Chihiros says it outright. The WRGB II product page carries the label “DISCONTINUED (FOR DISPLAY ONLY)” and reads “Sold Out,” with a $179.99 price still showing for the 30 cm variant. Clear, and to Chihiros’ credit.

Fluval says nothing. The Plant 3.0 pages resolve, render full specs, and look live. Open Fluval’s US lighting collection page and the line is not there: Plant 4.0 in five wattages, Plant Pro in four, Reef 4.0, Aquasky 3.0. Same on the UK collection page. An old product URL that still works is not evidence a product is still sold, on this brand or any other.

To Check NiCrew’s Recall Record, Look at the Remote and Not the Light

NiCrew recalled a product in 2024, and it is worth knowing which one. Health Canada’s recall notice, dated September 11, 2024, covers the remote control supplied with the 15-inch Submersible RGB Aquarium Light, model N21743. The remote “did not meet the performance, marketing, labeling, and instructional literature requirements for button or cell coin batteries.” 509 units were sold in Canada between March and August 2024, and as of September 10, 2024 the company had received no reports of incidents or injuries. The remedy is a replacement remote.

That is a different product from the ClassicLED Plus, which ships with no remote. If you keep a coin-cell remote of any kind in a house with small children, the hazard is real regardless of brand. I found no recall for the four fixtures compared here, from any of the four brands.

Which Planted Tank Light Should You Skip?

Skip the hygger if you need to know what you are getting. It wins this tally on the strength of a warranty and a wavelength list, and its one output figure — 201 to 420.1 — is unattached to any distance. I also could not retrieve a price from hygger’s own product page, which is why price scores 20.

Skip the NiCrew ClassicLED Plus if you are running CO2 or want a carpet. 1150 lumens across a 117-LED bar is a fish-viewing light that grows undemanding plants, and NiCrew publishes no PAR to argue otherwise. Its price also rendered to me in pounds on a US-facing domain, so check the currency before you check out.

Skip the Chihiros WRGB II Pro if you want to compare it to anything. $229.00 to $579.00 buys app control, four channels and a steel stand, and not one published number describing the light it makes. If you are buying it for how red plants photograph, that is a real reason and you already know it.

Skip the Fluval Plant 4.0 if the specs matter to you. It is the named loser at 35.5, and it lost to its own predecessor’s paperwork. No lumens, no LED count, no PAR table, no price numeral, no warranty duration — on a fixture whose 3.0 published every one of those and is still sitting on the same website proving it.

Prices are approximate, current as of publication, and change frequently — confirm the latest price with the retailer before buying.

Which Planted Tank Light Should You Buy?

After enough time around planted tanks, I’d trust the hygger over Fluval’s silence, since hygger names its wavelengths and backs them with a three-year warranty. 63.5 against 62.5 is not a result on its own. It is a coin toss with a decimal point on it, so here is mine.

I would spend my own money on the hygger. Three years on the housing against NiCrew’s one, published wavelengths, and a PAR figure that is at least a figure. NiCrew’s advantage is that its 1150 lm and 22 W are honest, checkable quantities; hygger’s is that it publishes more of the things a plant keeper actually needs. If you want the light for fish and a few anubias, take the NiCrew and save the difference. If plants are the point, take the hygger and accept that hygger has not anchored that number to a distance.

And since you are trusting my arithmetic: every figure in the decay table is Fluval’s, for a fixture Fluval no longer sells. That table is here because it is the only distance-tagged PAR data any of these four brands publishes. If Fluval put the same table back on the Plant 4.0, this page would be a different page.

Building the rest of the tank around the light? Start with how tank size changes the difficulty, since depth is what the table above is really about. Then filtration sized to stock and heater failure modes and watt sizing. More in Fish & Aquariums.