UNS Controsoil Review (2026): Specs, Startup, and Who It Suits

Exact product

Ultum Nature Systems

Ultum Nature Systems Controsoil (Black, Normal grain, 10 L)

Model: CON0110C

Best for

A planted or shrimp tank where you want soft, slightly acidic water without the big ammonia release of a rich soil.

Skip this if

You keep livestock that needs hard, alkaline water.

Type

Aqua soil: natural blend of soil and volcanic ash

Grain

Normal (UNS: the standard for larger aquariums and plants with thicker roots); Fine and Extra Fine also offered

Colors offered

Black, Brown

Bag sizes offered

1 L (2 gal tank), 3 L (9 gal tank), 10 L (20 gal tank)

pH effect

Buffers water to slightly acidic pH (about 6.8 over time) and lowers total water hardness

Ammonia

Low ammonia release; does not contain high nutrient levels that can cause ammonia spikes

Rinsing

No rinsing required

Strengths

• No rinsing required, per UNS.
• Low ammonia release compared with nutrient-rich soils, per UNS.
• Buffers toward slightly acidic, softer water.

Limitations

• Low built-in nutrients; fertilizer needed.
• Lowers pH and hardness, which not every tank wants.

Check Price on Amazon ↗ (opens Amazon in a new tab)Specs checked 2026-10-05. Prices and availability are on Amazon.

This review covers Ultum Nature Systems Controsoil, model CON0110C, in Black, Normal grain, 10 L bag. Controsoil also comes in Brown, in Fine and Extra Fine grains, and in smaller bags, so check color, grain, and volume on the listing before you order.

Specifications

Here is what the UNS product page states:

What these mean:

• Normal grain is, per UNS, the standard for larger aquariums and plants with thicker roots. Fine is aimed at foreground plants and Extra Fine at top-offs and nano tanks. UNS names grains only and does not give sizes in millimetres.
• Bag sizing. UNS pairs the 10 L bag with a 20 gal tank. A deeper bed, or sloping the substrate toward the back, takes more.
• Water chemistry. UNS says Controsoil provides pH and KH buffering and lowers total water hardness. That suits soft-water fish, shrimp, and plants, but it works against livestock that needs hard water.
• Low nutrients. UNS states Controsoil does not contain high nutrient levels; it says the soil releases minimal ammonia at the start, which helps kick off the cycle without added chemicals.

Suitable setups

• Shrimp tanks with species that prefer slightly acidic water; UNS describes it as suitable for fish and shrimp that prefer those conditions. Our shrimp guide covers water needs by species.
• Planted tanks of about 20 gal per 10 L bag, using the Normal grain for stem plants and root feeders.
• Keepers who already dose fertilizer or plan to, since the soil itself is lean.
• Low-tech or CO2 tanks, as long as the soft, buffered water suits your stock.

Strengths

• No rinsing required, per UNS, which says it actively absorbs impurities to inhibit cloudy water.
• Low ammonia release compared with nutrient-rich soils, per UNS, which can shorten the wait before livestock.
• Softens and buffers toward slightly acidic water, which many shrimp and soft-water plants prefer.
• Choice of grain and color to match the scape and plant type.

Limitations

• Low built-in nutrients. You will need a water-column fertilizer, and likely root tabs for heavy root feeders.
• Changes your water. Lowering pH and hardness is a drawback for livebearers, African cichlids, and other hard-water livestock.
• No published grain sizes in mm, which makes it harder to compare with other soils.
• Not inert. Like other aquasoils, its buffering is a property of the soil itself, so plan your water chemistry around it.

Compatibility and required extras

• Fertilizer. A comprehensive liquid fertilizer plus root tabs for swords and Cryptocoryne; see our fertilizer basics.
• Test kits. An ammonia and nitrite test for cycling, and a GH and KH test if you keep shrimp, since the soil lowers hardness.
• Enough soil. Use the UNS bag-to-tank pairing as a starting point and buy extra for a sloped scape. Our substrate guide covers depth.

Maintenance

• Do weekly water changes, which UNS recommends to prevent ammonia spikes.
• Avoid digging up the bed more than you need to; replant gently and vacuum only the surface.
• Watch pH and KH over time. Aquasoils buffer for a limited period, so readings drift as the soil ages; when buffering is exhausted or the grains break down, a substrate refresh may be due.

Alternatives

• ADA Aqua Soil Amazonia Ver.2: choose it if you want a nutrient-rich soil with an included supplement and can wait out a substantial ammonia release; ADA's own log recorded high ammonium for weeks before it cleared.
• Tropica Aquarium Soil Powder: choose it for a nano tank or carpeting foreground, thanks to its 1-2 mm grain, if you can do the frequent water changes Tropica recommends for the first 4 weeks.
• Seachem Flourite Black: choose it if you want a permanent, dark clay gravel that does not alter pH, for hard-water livestock or a substrate that never needs replacing.

For more detail, see Seachem Flourite vs UNS Controsoil, our planted aquarium substrate buying guide, or the Substrates: what to check before you buy ↗ hub.

Verdict

UNS Controsoil is a strong fit for soft-water planted tanks and shrimp tanks where you want an aquasoil with a gentler startup than nutrient-rich soils, and you are happy to fertilize. It is the wrong choice for hard-water livestock or for a no-dosing tank that relies on substrate nutrients. Whatever its low-ammonia billing, cycle the tank and test before adding animals. Unsure which substrate type fits your plan? Try the setup finder.